In order to realize the real-time automatic adjustment of the temperature of milk powder and milk liquid in the process of calf feeding and improve the accuracy of temperature control of heat exchanger, a dynamic temperature control technology of heat exchanger was designed by using fuzzy PID control algorithm. This technology mainly realized the dynamic adjustment of the controlled object (milk replacer solution) temperature by using PID parameter on-line fuzzy self-tuning and PID temperature control fuzzy algorithm, so as to ensure that the temperature of milk prepared with milk substitute powder was controlled within a controllable range of about (37±1)℃. According to the requirements that the temperature of milk preparation liquid of milk substitute powder for scientific calf feeding was 38~40℃,when the temperature of heat exchanger was set to be 42℃ and the entering water temperature adjusted to be 10℃, 15℃, 20℃ and 25℃ respectively, the maximum fluctuation range between the measured temperature of calf milk level and the preset temperature was only 0.3℃. The prototype performance test was carried out on the thermostatic control system of the heat exchanger of the calf feeding device. The thermostatic control of the hot water in the heat exchanger was set at 42℃, the time was recorded with a stopwatch and the temperature change was once every 5 min. During the whole test process, the temperature change range in the heat exchanger was basically controlled within（42±0.2）℃, and the average relative error and coefficient of variation of the temperature were small. The temperature control of the system was stable, which can meet the practical demand of calves for the temperature of milk replacer, and realize the rapid response and real-time temperature control of the heat exchanger of the calf feeding device.