The temperature is a key factor affecting the out power stability and lifetime of semiconductor laser diodes(LD)．For obtaining steady output power, ADN2830 and MAX1978 are used to provide a stable driving current for LD and to control the TEC, respectively. The magnitude and direction of the TEC were controlled by the control signal generated by proportional integral derivative (PID) compensating circuit. And meanwhile, the MAX1978 achieves the two-way control of the temperature of LD, so the LD can operate at a constant temperature. The experiment results show that the change rate of LD output power is less than 0.06% in the range of -35~45℃ and less than 0.16% in the range of -55~85℃.