Thermoelectric cooler has dynamic thermoelectric performance under complex environment.A linear dynamic model of the thermoelectric cooler was derived by using small-signal linearization method.It shows that the dynamic model of the thermoelectric cooler has one zero and two poles.The dynamic model of the thermoelectric cooler is showed to vary with operating conditions.Based on average linear dynamic model of a thermoelectric cooler,a temperature control system was designed for the cold end temperature of the thermoelectric cooler by using fuzzy-PID algorithm and Pulse Width Modulator.The step response tests show that the controller has satisfying dynamic and static performance.In room temperature environment,the response time for cooling down 10℃ is around 70s and the steady error is very small.the cold-end temperature can be maintained at the setting value within 0.1℃.Experiment results also show that the setting temperature can be 23℃ below the environment temperature.And the setting value is smaller,the