A temperature-control system for high-power semiconductor laser-diode with high precision was presents. In the system, a thermoelectric cooler was used to control the temperature of the laser-diode which realized the totally solid cooling system and a digital PWM power amplifier with high-precision was designed based on the characteristics of thermoelectric coolers. In the implementing process, single-chip micro-computer was used, and fuzzy PID method of which the parameters were self-turned on-line and nonlinear ompensation of the thermistor were accomplished through software. The results show that high control precision and small scillation can be gained and the temperature-controlling error of the system is ±0.06 ℃.