To clarify the comprehensive effects of a high-yield and high-efficiency cultivation mode (T) centered on technical measures including precision sowing, optimized planting density with reduced nitrogen input, furrow opening for yield enhancement, and winter plowing, a field experiment was conducted in Heshan District, Yiyang City, Hunan Province, in 2025. The experiment utilized early rice varieties Zhuliangyou 4024 and Zhongjiazao 17, along with late rice varieties Taiyou 398 and Taoyouxiangzhan. Using the local conventional cultivation mode as the control (CK), the study analyzed the effects of the two modes on grain yield and yield formation characteristics. The results showed that compared to CK, mode T significantly increased the yield of double-cropping rice, by 11.63% and 7.64% for early and late rice, respectively. Mode T primarily achieved this yield increase by enhancing the number of grains per panicle in early rice (increase of 20.03%) and the number of effective panicles in late rice (increase of 17.04%). Although there was no significant difference in the maximum tiller number between the two modes, the spike rate of mode T was significantly higher than that of CK, increasing by 9.35% and 21.45% for early and late rice, respectively. Furthermore, the total dry matter accumulation in mode T was significantly higher than that in CK, with the difference mainly attributed to the radiation use efficiency from heading to maturity. In conclusion, under conditions of reduced seed and nitrogen inputs, the high-yield and high-efficiency cultivation mode achieved increased yields in double-cropping rice by optimizing yield components, improving spike rates, and enhancing post-anthesis light utilization to boost dry matter accumulation.