In order to explore the effects of different rice irrigation patterns and nitrogen reduction on the decomposition characteristics of wheat straw returned to field and soil nutrients, an experiment using nylon net bag was conducted with the treatments as follows:1) rice irrigation patterns (conventional irrigation, W1; alternate wetting and moderate soil drying irrigation, W2); 2) nitrogen application levels (no nitrogen application, N0; conventional nitrogen application, N1; 20% reduction of conventional nitrogen application, N2). The decomposition and nutrient release of wheat straw and soil nutrient contents under different treatments were studied. The results show that both W2 and nitrogen application promote the decomposition of wheat straw returned to the field. N2 decreases the cumulative decomposition rate of wheat straw compared with N1. Under the same nitrogen application level, W2 increases the cumulative release rates of carbon, nitrogen, phosphorus and potassium of wheat straw compared with W1. N2 decreases the cumulative release rate of carbon, nitrogen, phosphorus and potassium of wheat straw compared with N1. W2 and nitrogen application increase the contents of soil organic matter, total nitrogen, available nitrogen and available phosphorus, while N2 has little effect on the contents of soil nutrients compared with N1. In conclusion, W2 and nitrogen application promote the decomposition and nutrient release of wheat straw returned to field, which is conducive to the improvement of soil nutrients, while N2 has no significant effect on the decomposition and nutrient release of wheat straw and soil nutrients.