NOVELTY - An automatic marsh gas desulfurization control system for detecting methane, hydrogen sulfide, and oxygen content, comprises a marsh gas desulfurization reaction area gas content control system and a marsh discharging area gas content detecting system; where the marsh gas desulfurization reaction area gas content control system is set with an air flow meter (1), an air inlet automatic adjusting valve (2), a marsh inlet automatic adjusting valve (3), a marsh gas flow meter (4), a first oxygen probe (5), a first oxygen alarming device (6), and a data collecting/analyzing/dispatching device (8).    USE - The automatic marsh gas desulfurization control system is useful for detecting methane, hydrogen sulfide, and oxygen content (claimed).    ADVANTAGE - The automatic marsh gas desulfurization control system monitors the marsh gas desulfurization reaction area gas content in real time to achieve high-efficiency and safe marsh gas desulfurization. Moreover, it monitors the marsh gas discharging area gas content online to ensure the safe use of the purified marsh gas. Additionally, it runs the marsh gas desulfurization continuously through the automatic control and recycles the sulfur elemental substance.    DETAILED DESCRIPTION - An automatic marsh gas desulfurization control system for detecting methane, hydrogen sulfide, and oxygen content, comprises a marsh gas desulfurization reaction area gas content control system and a marsh discharging area gas content detecting system. The marsh gas desulfurization reaction area gas content control system is set with an air flow meter (1), an air inlet automatic adjusting valve (2), a marsh inlet automatic adjusting valve (3), a marsh gas flow meter (4), a first oxygen probe (5), a first oxygen alarming device (6), a dissolved oxygen probe (7), and a data collecting/analyzing/dispatching device (8); the air flow meter is connected to the marsh gas desulfurization reaction area through the air inlet automatic adjusting valve; the marsh gas flow meter (4) is connected to the marsh gas desulfurization reaction area through the marsh gas inlet automatic adjusting valve; the marsh gas desulfurization reaction area is set with the first oxygen probe and the dissolved oxygen probe; one end of the first oxygen alarming device (6) is connected to the first oxygen probe; the marsh gas discharging area gas content detecting system comprises a hydrogen sulfide alarming device (9), a hydrogen sulfide probe (10), a second oxygen probe (11), a marsh gas discharging automatic adjusting valve (12), and a second oxygen alarming device (13); the marsh gas discharging area is set with the hydrogen sulfide probe (10) and the second oxygen probe; one end of the hydrogen sulfide alarming device is connected to the hydrogen sulfide probe; one end of the second oxygen alarming device is connected to the second oxygen probe; one end of the marsh gas discharging automatic adjusting valve is connected to the marsh gas discharging area; the marsh gas discharging area is connected to the marsh gas desulfurization reaction area; and the data collecting/analyzing/dispatching device is connected to the other end of the first oxygen alarming device, the other end of the hydrogen sulfide alarming device, the other end of the second oxygen alarming device, the air inlet automatic adjusting valve, the marsh gas inlet automatic adjusting valve, the dissolved oxygen probe, and the marsh gas discharging automatic adjusting valve. An INDEPENDENT CLAIM is an automatic marsh gas desulfurization control method for detecting methane, hydrogen sulfide and oxygen content; where the dissolved oxygen probe monitors the content of the dissolved oxygen of the liquid phase in the marsh gas desulfurization reaction area in real time and controls the air inlet automatic adjusting valve and the marsh gas inlet automatic adjusting valve to adjust the inlet quantity and proportion of the methane and the air according to the data collecting/analyzing/dispatching device; the concentration of the liquid phase part of the dissolved oxygen of the marsh gas desulfurization reaction area is kept within 0.05-0.10 mg/L; the first oxygen probe monitors the content of the oxygen of the marsh gas desulfurization reaction area so that the oxygen volume proportion content of the gas phase of the marsh gas desulfurization reaction area is less than 1.0%; if the oxygen volume proportion content of the marsh gas desulfurization reaction area is larger than 1.0%, the first oxygen alarming device sends the alarming; the data collecting/analyzing/dispatching device further control the air inlet automatic adjusting valve and the marsh gas inlet automatic adjusting valve to adjust the inlet quantity and proportion of the methane and the air; the oxygen volume proportion content of the gas phase of the marsh gas desulfurization reaction area is less than 1.0%; the first oxygen alarming device stops the alarming; the hydrogen sulfide probe measures the hydrogen sulfide content of the marsh gas discharging area content detecting system; if the detected hydrogen sulfide content is larger than 20 mg/m3; the hydrogen sulfide alarming device sends the alarming; the data collecting/analyzing/dispatching device makes the marsh gas discharging automatic adjusting valve at the closing state; the inlet quantity of the marsh gas of the marsh gas desulfurization reaction area is adjusted and controlled until the content of the hydrogen sulfide of the marsh gas discharging area is less than 20 mg/m3; the hydrogen sulfide alarming device stops the alarming; the second oxygen probe measures the oxygen content of the marsh gas discharging area content detecting system; if the detected oxygen content is larger than 1.0%, the second oxygen alarming device sends the alarming; the data collecting/analyzing/dispatching device makes the marsh gas discharging automatic adjusting valve at the closing state; the inlet quantity of the air of the marsh gas desulfurization reaction area is adjusted and controlled until the oxygen content of the marsh gas discharging area is less than 1.0%; and when the hydrogen sulfide alarming device and the second oxygen alarming device cannot send the alarming, the data collecting/analyzing/dispatching device makes the marsh gas discharging automatic adjusting valve at the opening state to discharge the marsh gas outwardly.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the automatic marsh gas desulfurization control system for detecting methane, hydrogen sulfide, and oxygen content.    Air flow meter (1)    Air inlet automatic adjusting valve (2)    Marsh inlet automatic adjusting valve (3)    Marsh gas flow meter (4)    First oxygen probe (5)    First oxygen alarming device (6)    Data collecting/analyzing/dispatching device (8)