Accurate control of the temperature of photoacoustic systems is helpful to improve the detection sensitivity and stability. The temperature controller is composed of microcontroller STC12C5A60S2 and temperature sensor Pt1000. The four-wire method of Pt1000 effectively eliminates the error due to the lead resistance. The temperature signal processing circuit adopts instrument amplifier AD620. 14 bit high rate ADC (analog to digital converter) TLC3574 is used to transfer temperature voltage acquired by microcontroller and its reference voltage is provided by LM4040. The driver circuit of Peltier is H-bridge MOSFETS controlled by PWM wave from STC12C5A60S2. The duty ratio of PWM wave determines the current direction and conduction time to realize heating or cooling. The control range of temperature is from 0 ℃ to 40 ℃ and the sensitivity is 0.06 ℃.