Abstract: As a specific form of new quality productive forces in agriculture, the new quality productive forces in paddy fields represent an endogenous driving force that enhances rice production efficiency within the broader framework of new quality productive forces. The force takes the paddy field ecosystem as the target, scientific and technological innovation as the engine, and the integration of new productive factors into the rice industry chain as the principle, achieved through the recombination of these factors. The development of new quality productive forces in paddy fields is a critical proposition in the new era for ensuring national food security and advancing high-quality agricultural development. Facing multiple challenges such as technological bottlenecks, economic costs, ecological risks, and farmers’ acceptance, it is worth studying how government subsidy policies can serve as a tool to promote the growth of new quality productive forces in paddy fields. This paper focuses on the perspective of farmers in paddy field management. Based on survey data from 559 farmers in 10 counties of Jiangxi Province, this study constructs benchmark regression, mediating effect, and moderating effect models, and employs methods such as DEA and Tobit regression to conduct an in-depth analysis of the impact and mechanism of government subsidies on the new productive forces in paddy fields. The results show that: First, government subsidies promote the development of new quality productive forces in paddy fields. This conclusions remain consistent following the robustness test and endogeneity treatment; Second, government subsidies demonstrate heterogeneous effects on the development of new quality productive forces in paddy fields, contingent upon farmers’ risk attitudes and the land contiguousness, and there is an interactive inhibitory effect between the impact of risk attitude and land contiguousness on the new quality productive forces in paddy fields; Third, social learning is identified as a significant mediating mechanism through which government subsidies facilitate the development of new quality productive forces in paddy fields. Government subsidies promote the development of new quality productive forces in paddy fields by improving the level of social learning of farmers; Fourth, rice insurance serves as a moderating factor in the process of government subsidies affecting new quality productive forces in paddy fields, attenuating the positive effect of government subsidies on new quality productive forces in paddy fields, and the two exhibit a substitution effect. Therefore, it is essential to optimize government subsidy policies, enhance the differentiation of subsidy policies, establish a social learning support system, and improve the coordination mechanism between rice insurance and subsidy policies.