The traditional water temperature regulation adopts manual experience and semi-electrical automation. These methods have the problems of single structure, large water temperature fluctuation and poor stability. Therefore, a PID correction control system based on increment is designed. Based on incremental PID correction control system, thermal resistance is used as temperature sensitive element, and a three-wire thermal resistance temperature data acquisition bridge circuit is designed. According to the experimental temperature data and its thermal resistance, the correction coefficient is calculated to reduce the data output error. Finally, the experimental prototype is designed and made to verify the correctness of the theoretical analysis according to the data obtained from the prototype.