To address the issue of output wavelength drift in distributed feedback（DFB）semiconductor lasers caused by unstable temperature control circuits, a temperature control system for semiconductor lasers based on sliding mode control is designed. The system employs curve fitting to derive the transfer function of the thermoelectric cooler（TEC）inside the DFB semiconductor laser. A temperature simulation model was constructed in Simulink by incorporating white noise, and the feasibility of proportional-integral-derivative（PID）control, incremental PID control, and sliding mode control is compared. Finally, the temperature control waveforms under different algorithms are compared in the experimental circuit. The experimental results show that by optimizing the design of the sliding mode control system, the response speed and steady-state accuracy of the laser system can be effectively improved. After prolonged testing, the temperature error within a continuous 120-minute period is less than or equal to 0.16%.