相对于外腔半导体激光器，分布式反馈(Distributed Feedback Laser，DFB)激光器的温调率较高，为实现饱和吸收稳频，需要对激光器温度进行精密控制。分析了饱和吸收稳频系统的控温需求，基于MAX1978芯片设计了精密温控系统；利用恒流源对测温电桥电路进行了线性优化，利用遗传算法对模拟PID电路参数进行快速整定，系统最终实现0.2mK的控温稳定度，比同类设计的稳定度高1~2个数量级，解决了饱和吸收谱线明显晃动的问题，具有广阔的应用前景。

Compared with the external cavity semiconductor laser, distributed feedback laser has a higher temperature regulation rate. In order to achieve saturated absorption frequency stabilization, it is necessary to control the laser temperature precisely. In this paper, the temperature control requirements of the saturated absorption frequency stabilization system is analyzed, a precise temperature control system is designed based on MAX1978 chip.The linear optimization of the temperature bridge circuit is realized by using constant current source, and the parameters of the analog PID circuit are quickly adjusted by using genetic algorithm. Finally the temperature control stability of 0.2mK is achieved, which is 1~2 orders of magnitude higher than that of the similar design. It solves the problem of obvious shaking of saturated absorption spectrum and has a broad application prospect.