NOVELTY - The system comprises a fermentation jar, a drying tower, a water tower, an absorption tower, a hot water tank and a lifting system. The lifting system comprises a heat exchanger, a biogas residue tank through a pipeline, a liquid circulation pump, a water source heat pump, a heat storage tank, a heat pump and a hot water jar. The heat exchanger is provided with a water inlet through the pipeline and connected to the biogas residue tank. The fermentation jar is connected to the pipeline and the hot water tank. The water source heat pump is provided with a water outlet through the pipeline.    USE - The system is useful for recovering heat waste generated by a marsh gas plant (claimed).    ADVANTAGE - The system has reduced energy consumption and cost in an economical manner.    DETAILED DESCRIPTION - The system comprises a fermentation jar, a drying tower, a water tower, an absorption tower, a hot water tank and a lifting system. The lifting system comprises a heat exchanger, a biogas residue tank through a pipeline, a liquid circulation pump, a water source heat pump, a heat storage tank, a heat pump and a hot water jar. The heat exchanger is provided with a water inlet through the pipeline and connected to the biogas residue tank. The fermentation jar is connected to the pipeline and the hot water tank. The water source heat pump is provided with a water outlet through the pipeline. The heat storage tank is connected to the water source heat pump and provided with the water outlet. The heat pump is provided with a second water pump and the pipeline. The water source heat pump is provided with the water inlet and connected to a hot water outlet. The drying tower is provided with the water outlet through an air compressor, a water pump and the pipeline and connected to the hot water jar. The water tower is provided with a water inlet pipeline and a water jar. The hot water jar is provided with a temperature sensor. The temperature sensor and the air compressor are connected to the water pump. The absorption tower and the water jar are provided with the water source heat pump and a refrigeration system. The refrigeration system comprises a waste heat air conditioner and a hot water machine. The waste heat air conditioner is provided with the water outlet through the pipeline and the hot water jar and connected to the air conditioner. The hot water machine is provided with the hot water outlet and the absorption tower.