The invention discloses an agricultural water and soil improvement irrigation and drainage system. The agricultural water and soil improvement irrigation and drainage system is characterized in that a coarse screen and a fine screen are mounted in a screen well, the fine screen is horizontally mounted in the screen well and covers a rainwater purifying rubble layer at the bottom, an aeration regulation pool, a hydrolysis acidification pool and a contact oxidation pool are serially connected below the rainwater purifying rubble layer, a steel perforated top plate is arranged at the upper end of a regulation and storage unit, the aperture ratio of the steel perforated top plate is 60-70%, the pore diameter is 5-7 mm, a planting pool is arranged at the top of the steel perforated top plate, rainwater infiltrates into the regulation and storage unit via the planting pool to be stored, one side of the regulation and storage unit is connected with a third lift pump through a water conveying pipe, the water outlet end of the third lift pump is connected with a water outlet through a water conveying pipe, the water outlet is positioned right above a water storage tank, and an irrigating layer is mounted in the planting pool, formed by connecting a plurality of irrigation water pipes through five-way connectors and pre-buried in the planting pool. The agricultural water and soil improvement irrigation and drainage system realizes efficient utilization of water sources, and meanwhile, realizes rainwater purification, regulation, storage and recycling.