In this study, six treatments, no nitrogen(CK), conventional urea(U), controlled-release nitrogen fertilizer at full(CRU), 10%(CRU1), 20%(CRU2), and 30%(CRU3) reduced nitrogen rates were performed in a field experiment in double-cropping rice fields from 2020 to 2021. The goal of this experiment was to examine the effects of reduced controlled-release nitrogen on nitrogen runoff loss, rice yield, and nitrogen use efficiency. The results indicated that compared with the U treatment, total nitrogen(TN) runoff losses under CRU1, CRU2, and CRU3 treatments were significantly reduced. In 2020, early rice TN losses under CRU1, CRU2, and CRU3 treatments decreased by 57.99%, 74.58%, and 78.49%, and late rice losses decreased by 60.80%, 63.89%, and 66.05%, respectively, while in 2021, early rice TN losses decreased by 55.08%, 63.77%, and 72.12%, and late rice losses decreased by 42.18%, 66.67%, and 75.36%, respectively. TN runoff loss decreased as nitrogen application rates declined. Ammonium nitrogen(NH??-N) was the primary form of nitrogen runoff loss, ranging from 0.50 to 7.98 kg/hm2 and accounting for 28.40%-64.57% of TN loss in nitrogen fertilizer treatments. Compared with the U treatment, controlled-release nitrogen fertilizer reduced treatments significantly increased agronomic efficiencies, partial factor productivities, and absorption and utilization rates of nitrogen fertilizer by 25.69%-37.63%, 13.48%-42.24%, and 9.55%-40.53%, respectively, while maintaining rice yields. CRU3(30% reduction) treatment performed best. In conclusion, reduced controlled-release nitrogen application effectively lowered nitrogen runoff loss, improved nitrogen use efficiency, and stabilized rice yield, making it suitable for southern double-cropping rice systems.