Objective Hypothermia therapy can reduce the size of myocardial infarction, increase myocardial survival, and improve long-term prognosis. In view of the problems that the domestic hypothermia therapeutic devices generally use exogenous perfusion fluid for perfusion treatment, which have many adverse reactions, the devices have large volume and weight, and the temperature control accuracy is not high, the article designs a portable and accurate temperature-controlled coronary artery hypothermia control device based on extracorporeal blood circulation. Methods In the temperature control system, semiconductor cooling chips are used as cold sources, and the cooling device is redesigned and combined with fuzzy PID control technology to achieve accurate temperature control. The temperature control system model is established, the system parameters are identified using the step response method, and finally the experimental platform for temperature control experiments is set up. Results The hypothermia control device for extracorporeal blood circulation coronary artery has a simple and easy structure, and strong anti-interference ability. In the experiment of temperature control capability of the controlled liquid, the temperature response is rapid, reaching the set temperature quickly, and the steady-state error is within ± 0.1℃ . In the simulated hypothermia control experiment, the temperature of the mixture reached the set temperature in 145 seconds after the start of the experiment and remained stable at 34 ± 0.1℃ . Conclusions The hypothermia control device proposed in this article has greatly improved portability and temperature control accuracy compared with conventional equipment, and is of great significance for improving the life quality of life of patients with myocardial infarction.