A field experiment was conducted in the red soil hilly region in the early-rice season in 2018 to examine the effects of lime on decomposition and nutrient release characteristics of rapeseed straw and rice yield formation. The results showed that applying lime or rape straw to the field significantly increased the yield of early rice, and the two had a significant interaction effect. The application of lime significantly promoted the decomposition and nitrogen release of rape straw in the early and mid-term after returning to the field, but had no significant effect on the release of phosphorus and potassium. Rape straw returning to the field combined with lime application increased tillering and effective panicle, nutrients（N, P, K） absorption, dry matter accumulation and simultaneously increased the number of effective spikes and grains per panicle, thus expanded the population storage capacity. It can be seen that in acid red soil rice fields, returning rape straw to the field and applying lime accelerated its own decomposition and nitrogen release, and increased rice yield.