The invention relates to an underground water, fertilizer and gas integrated irrigation system, and belongs to the field of irrigation management. The underground water, fertilizer and gas integrated irrigation system comprises a water source, a water and fertilizer coupling system, an air-entrapping system, an active transport system, an irrigation system and a control system, wherein the water source comprises a running water inlet pipe opening and a check valve; the water and fertilizer coupling system comprises a water inlet valve, a fertilizer mixing tank, a fertilizer mixing valve, a fertilizer storage tank, a flow meter, a filter, a fertilizing pump and a water check valve; the air-entrapping system comprises an air compressor and an electromagnetic valve; the active transport system comprises a transport main pipe; the irrigation system comprises an irrigation main pipe, an irrigation branch pipe, an irrigation hollow billet and a water dropper; and the control system comprises a soil humidity control circuit and an atmospheric pressure test circuit. According to the underground water, fertilizer and gas integrated irrigation system, a certain amount of water and a certain quantity of a fertilizer are provided according to the requirements of crop growth; the root of a plant is ventilated to meet the condition that the root is subjected to aerobic respiration to maintain metabolism and growth and development of the overall plant; the use amount of water and the use quantity of the fertilizer can be effectively reduced; the management is optimized; the labor force is reduced; and the yield is increased.