Abstract: Ground cover rice production system (GCRPS) demonstrates significant water-conserving and temperature-raising impacts that mitigate seasonal drought and early low-temperature stress in rice cultivation across hilly and mountainous area. By utilizing plastic film or other mulching materials, GCRPS effectively reduces soil water evaporation, conserves soil moisture, and elevates root-zone temperature. Despite these benefits, prevalent fertilizer management practices under GCRPS—often relying on a one-time, basal application of chemical nitrogen—frequently result in undesirable crop growth patterns. Specifically, this approach can cause excessive growth in the early stages and nitrogen (N) deficiency during later stage. To systematically investigate and optimize N management strategies for GCRPS, a field experiment conducted from 2021 to 2022 was carried out in the hilly area of Ziyang city, the central Sichuan Province. Two water treatments (W1, conventional flooding paddy; W2, GCRPS) and three N treatments (N1, zero-N fertilizer; N2, 135 kg /hm² as a urea-based fertilizer; and N3, 135 kg /hm² of urea with a 3:2 base-topdressing ratio for the W1 or a 67.5 kg /hm² each of urea and manure as basic fertilizer for W2) were designed. Beyond the field experiment, the study adopted a holistic, multi-objective optimization framework. The goal was set to maximize economic benefits, subject to the constraints of yield and environmental impacts. These were combined with the various scenario simulations of N application and organic fertilizer substitution rate from the WHCNS (Soil Water Heat Carbon Nitrogen Simulator) model. An N fertilizer management model for GCRPS was constructed based on the multi-objective synergies of yield, environmental and economic goals. Ultimately, the optimal ratio and quantity of combined organic-inorganic fertilizer application for GCRPS were determined. The results showed that the coefficients of determination between simulated and measured values for the constructed N fertilizer management model were all above 0.95 and significant at the 0.001 level. These robust validation results unequivocally demonstrate that the model excellently simulates the crop yield and N losses under GCRPS, providing a reliable tool for scenario management optimization. Taking 2022 as an example, compared with the original strategy of 50% organic fertilizer substitution (with a total N application rate of 135 kg /hm²), the N loss of the 64% organic fertilizer substitution strategy (with a total N application rate of 157.9 kg/hm²) remained the same. Notably, this strategy increased yield and net profit by 41 kg/hm² and 45 CNY/hm², respectively. This outcome effectively demonstrates the potential to achieve increased production and efficiency without increasing pollution, a core principle of sustainable intensive agriculture. In conclusion, this strategy is recommended as the optimal approach for integrates organic-inorganic fertilization in GCRPS within this region. The N fertilizer optimization framework developed in this study successfully identifies management practices that synergistically maximize net economic benefits, secure high and stable yields, and safeguard the environment by preventing additional nitrogen pollution. Therefore, this research delivers a robust scientific basis and practical technical guidance for the precise, efficient, and environmentally sound application of nitrogen fertilizers in ground cover rice production systems, contributing directly to the advancement of green and sustainable rice cultivation in vulnerable mountainous regions.