Optimal Allocation of Regional Defense Resources Based on POS Optimization Algorithm

China’s water resources are becoming increasingly tense. In order to support the sustainable development of limited water resources, it is necessary to improve the research on water resource allocation. Based on the domestic and foreign research on the optimal allocation of agricultural water resources, combined with the actual needs of the city, the optimal POS algorithm is used to optimize the allocation of urban water resources, and an optimal water resource allocation model is created. This paper describes the optimal POS algorithm, and on this basis, the optimal POS algorithm is applied to the characteristics and complexity of optimal water resources decision-making. In this paper, the POS optimization algorithm is used to solve the problem. Obtain the results of urban water resource allocation with different guarantee rates in 2024 and 2030, conduct rational analysis in combination with the future water supply situation, and give corresponding suggestions. Experimental research shows that by 2027, the city’s industrial water recycling rate will increase from 34% to over 60%. By 2030, the city’s industrial water recycling rate will increase to over 82%.