Aiming at the problems of low control precision and slow response speed of the existing food drying equipment thermostatic control system, this paper presents and designs a kind of food drying equipment thermostatic control system based on platinum resistance as temperature sensing device and hardware closed-loop control circuit for constant temperature control. The test results show that the constant temperature error of the system is within ±0.1 ℃, and the average response time of constant temperature is 4 min 56 s, which can effectively improve the system constant temperature control accuracy and response speed.