NOVELTY - Producing ammonia by converting natural gas comprises feeding 70-80% of natural gas which is compressed by two stages (6.52 MPag and 135.7 degrees C) and contains 10 mg/L of total sulfur, together with oxygen from air, into two gasification furnaces by a nozzle; performing partial oxidization in reacting chamber, controlling temperature in gasification furnace at 1100-1200 degrees C by controlling ratio of oxygen/natural gas; recovering cold amount in circulating gas from separator, delivering gas to synthetic gas compressor inlet, evaporating, and condensing.    USE - Method for producing ammonia by converting natural gas.    ADVANTAGE - The method has low investment and low energy consumption.    DETAILED DESCRIPTION - Producing ammonia by converting natural gas comprises:    (A) feeding 70-80% of natural gas which is compressed by two stages (6.52 MPag and 135.7 degrees C) and contains 10 mg/L of total sulfur, together with oxygen from air, into two gasification furnaces by a nozzle;    (B) performing partial oxidization in reacting chamber, controlling temperature in gasification furnace at 1100-1200 degrees C by controlling ratio of oxygen/natural gas to generate roughly synthetic gas taking hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2) as raw materials and little methane;    (C) desulfurizing 20-30% of natural gas, mixing with medium pressure steam, controlling mass ratio of water to carbon at 3:1, pre-heating mixing gas to 540-560 degrees C, and delivering into heat exchange type converter;    (D) performing conversion reaction of natural gas and medium pressure vapor in conversion tube containing nickel catalyst to generate oxide of hydrogen and carbon, where gas from heat exchange type converter is under 9.3 MPag and 860 degrees C, and contains 7.75 (mol)% of methane;    (E) exchanging heat of technology gas from gasification furnace and heat exchange type converter, feeding high temperature dry gas which is at 547.8 degrees C into exchange system, filling steam, and delivering into rinsing saturation tower to saturate the gas by condensate from the exchange system;    (F) filling required amount of steam into mixing gas, heating to 320 degrees C by outlet gas of conversion system, and feeding into the conversion system;    (G) converting partial CO into CO2 under function of catalyst, releasing reaction heat, and delivering technology gas on the outlet containing 0.412% of CO into decarbonization system;    (H) by liquid nitrogen washing technology under deep cooling condition, gradually cooling technology gas to - 188 degrees C by gas refining unit, and during cooling, condensing methane at - 175-185 degrees C;    (I) separating most methane out of technology gas in form of liquid phase, decompressing liquid phase methanol to 1.5 MPa, recovering cold, re-heating and recycling;    (J) re-heating carbon monoxide, methane and argon in gas phase into interface zone and using as fuel;    (K) filling high-purity nitrogen into purified technology gas, regulating mass ratio of hydrogen to nitrogen at 3:1, and delivering into synthetic gas compressor;    (L) compressing synthetic gas by compressor by three stages, increasing pressure of circulating gas to 151 bar (G), heating outlet gas of third synthesis tower and the outlet synthetic gas of first synthesis tower to 380 degrees C, and delivering into first synthesis tower;    (M) controlling outlet gas of first synthesis tower at 497.2 degrees C, decreasing temperature of pre-heated feeding gas of first synthesis tower to 380 degrees C, and delivering into second synthesis tower;    (N) controlling temperature of outlet gas of second synthesis tower at 472.8 degrees C, decreasing temperature to 380 synthesis tower, and delivering into third synthesis tower;    (O) controlling temperature of outlet gas of third synthesis tower as 442.2 degrees C, delivering synthetic gas to outlet of synthetic gas compressor, cooling to 4.4 degrees C and delivering into the separator; and    (P) recovering cold amount in circulating gas from separator, delivering gas to synthetic gas compressor inlet, evaporating, condensing and reducing voltage of liquid ammonia from separator, and delivering obtained liquid ammonia product to urea device.    An INDEPENDENT CLAIM is included for an ammonia producing device which comprises gasification furnace, heat exchange type converter, rinsing saturation tower, exchange system, decarbonization system, gas refining unit, synthetic gas compressor, first synthesis tower, second synthesis tower, third synthesis tower, separator and urea device, where inlet of gasification tower is connected with the natural gas and oxygen feeding nozzles, and outlet is connected with shell range inlet of heat exchange type converter conversion pipe. The natural gas and medium pressure steam inlet of heat exchange type converter is connected with conversion pipe. Outlet of conversion pipe is connected with shell range inlet. Shell range outlet of the conversion pipe is connected with shell range of exchange system which is connected with steam pipeline. Shell range outlet of exchange system is connected with rinsing saturation tower which is connected with condensate outlet of exchange system. The outlet of rinsing saturation tower is connected with reaction pipe of the exchange system which is connected with the decarbonization system. The decarbonization system is connected with gas refining unit and urea device. Synthetic gas compressor is connected with gas refining unit, and is connected with separator by first synthesis tower, second synthesis tower and third synthesis tower. Circulating gas outlet of separator is connected with synthetic gas compressor. The liquid ammonia outlet of separator is connected with urea device.