NOVELTY - The comprehensive utilization system comprises an anaerobic fermentation tank arranged in a pipe irrigation system, where the anaerobic fermentation tank includes a top layer for collecting a marsh gas that is stored in a marsh gas tank, a desulfurization device connected with a combustion gas generator for generating high temperature flue gas, a heat power generation device connected with the gas generator, a cooling device used to keep the temperature of the reaction liquid in the anaerobic fermentation tank, an irrigation system pipe connected with a gas valve through a gas pipeline.    USE - The comprehensive utilization system is useful for producing marsh gas that is used in agricultural planting applications (claimed).    ADVANTAGE - The system can produce more marsh gas so as to improve crop planting with high efficiency.    DETAILED DESCRIPTION - The comprehensive utilization system comprises an anaerobic fermentation tank arranged in a pipe irrigation system, where the anaerobic fermentation tank includes a top layer for collecting a marsh gas that is stored in a marsh gas tank, a desulfurization device connected with a combustion gas generator for generating high temperature flue gas, a heat power generation device connected with the gas generator, a reaction liquid poured into the anaerobic fermentation tank, a cooling device used to keep the temperature of the reaction liquid in the anaerobic fermentation tank, an irrigation system pipe connected with a gas valve through a gas pipeline. A solid liquid separator separates the fermentation liquid at an upper layer of the anaerobic fermentation tank. An aeration device is connected with a biogas pool, and includes a large screen area with a filter screen shower for filtering a biogas slurry in a solid block through the pipeline in the pool. A mulching film is located on a head part of an irrigation device through a lower part so as to reduce smoke gas flow speed, slow release effect and carbon dioxide emissions. A pipeline irrigation system includes a biogas valve, a flue gas valve, an electronic-controlled valve, a temperature sensor, a humidity sensor and a carbon dioxide concentration sensor. An INDEPENDENT CLAIM is included for producing marsh gas for agricultural planting applications.