<p>Hydrothermal geothermal resources represent a form of renewable energy. The optimization of the heat-storage system’s operation is a crucial determinant for maximizing the reservoir’s heat production and ensuring its sustainable utilization. In this study, a three-dimensional water-heat coupling numerical model of the sandstone reservoir was developed using temperature data from sandstone formations and field-measured data. Through comprehensive analysis and simulation of real-world scenarios, an in-depth analysis was conducted on the geothermal potential of the reservoir and the impacts of various development strategies on reservoir temperature. These strategies mainly encompass aspects such as production-reinjection patterns, reinjection ratios, production flow rates, well spacing, and reinjection temperatures. The computational results indicate that during the long-term operation of the actual well group, the reservoir temperature experiences a significant decline. After optimization, the appropriate parameter settings for this geothermal field are as follows: under a three-production and three-reinjection configuration, a reinjection ratio of 1:1:3, a production flow rate of 55 m³/h, a well spacing of 415 m, and a reinjection temperature of 20 °C. The related findings and optimization methods could guide the system design of the hydrothermal geothermal project for the decision-maker.</p>