Abstract: To provide effective measures for total wheat strawreturn to soilin rice-wheat rotation mode, a field experiment was conducted to study the application of decomposing microorganism under total wheat straw return. The experiment was carried out with3treatments, which were treated with CK (no decomposing agent), decomposing agent A and decomposing agent B, respectively. The results showed that decomposing agent A reduced rice yield by 2.37% , decomposing agent B increased rice yield by1.74% . Compared with CK, decomposing agent A increased the contents of available NPK in paddy soil by 2.34mg/kg,1.00mg/kg and 4.00mg/kg, respectively, and decreased the content of copper and zinc, and increased the content of arsenic by 3.03mg/kg. Decomposing agentBreduced the contentofavailable NP and organic matter in paddy soilby5.33mg/kg, 6.47mg/kg, and3.66g/kg, respectively, and decreased the content of copper, zinc and arsenic. The application of decomposing agent A and B could promote soil microorganism proliferation, enhance the overall metabolic activity and increase species diversity index. Decomposing agent A increased the number of bacteria and fungi significantly, but decomposing agent B increased the number of actinomyces more obviously. Based on the synthetic effectsonrice yield, soil physical and chemical properties, microorganism population and metabolic characteristics, the application of total wheat straw return combined with decomposing agent B was more favorable to rice yield and soil health.