With the rapid development of the injection molding industry, the performance requirements of injection molding machines are increasing day by day, especially the requirements for temperature control accuracy. Temperature control plays a crucial role in the injection molding process, which directly affects the quality and production efficiency of the product. Although the traditional PID control is effective in many cases, its fixed parameters often can not meet the needs of real-time changes when facing a complex dynamic environment. Therefore, a temperature control method for injection molding machines based on a self-regulating PID control algorithm is proposed in this paper. This method can adjust the parameters of the PID controller in real-time to cope with the influence of temperature fluctuation, system aging, and external interference in the process of injection molding, and improve the precision and stability of temperature control. The simulation results show that when the ambient temperature is 260 °C, the adaptive PID algorithm has a shorter temperature adjustment time, and faster response speed, and both overshoot and steady-state error are 0. Compared with the traditional PID control algorithm, the control effect of the fuzzy PID control algorithm has been significantly improved.