The invention discloses a water-fertilizer conditioning method for rice straw mulching and returning in wheat season, which belongs to the field of water-fertilizer conditioning of crops, in particular to a water-fertilizer conditioning technology under the rice straw mulching and returning way in the small spring wheat season of Chengdu Plain. In the Chengdu Plain, rice straws harvested in the previous season are used for total mulching and returning, thereby carrying out quantitative water regulation and soil fertilizer conditioning during the whole growth period of wheat; the method combines the straw total returning with the water-fertilizer conditioning technology, thereby avoiding the possible negative effects to the soil caused by simple returning during the straw decomposition process, integrating the cultivation technology which is matched with straw returning, optimizing a system of fast conversion and utilization of straws and the crop stable and high yield technology and designing the reasonable water-fertilizer conditioning scheme; furthermore, the tillage measures can not only improve the yield of the crops, save the labor force and improve the economic benefits, but also retain water and fertilizer, improve the soil structure, protect the environment and promote the sustainable development of agriculture in the region.