A temperature feedback PWM adjustment circuit has been proposed. The circuit could automatically pulse width modulate the common cathode voltage according to temperature changes， so as to maintain the brightness and gray-scale characteristics of the OLED screen with the temperature changing. The circuit used 0.18 μm 1P6M mixed-signal technology to complete the circuit design and tape-out verification. Simulation and test results showed that when the temperature changed from -45 °C to 70 °C， the screen brightness and grayscale characteristics remained unchanged. In the end， the problem about the brightness of the OLED screen changing with temperature， and the traditional solution changing the gray-scale characteristics were solved.