In order to eliminate the overshoot of the pure hysteresis system and ameliorate the influence of temperature factors on the quality and strength of the fabricated parts, a temperature control system based on BP-PID algorithm for selective laser sintering was designed. In this system, the hierarchical architecture and modular design scheme were adopted, STM32 controller was used as the main control module, and BP neural network was used to improve the traditional PID algorithm, which improved the stability of the control system and had remarkable effect. By uing MATLAB, the simulation was carried out, and the simulation results were compared with traditional PID control. The test was carried out.The results show that by using BP-PID algorithm, the optimal parameters can be quickly set, the overshoot is small, and the time to reach the steady state is shorter;when the preheating temperature is set at 90 ℃ and the BP-PID algorithm is adopted to control the system, the steady-state error is within ±1 ℃ and the overshoot is less than 3%.