Embodiments of the present disclosure provide an adjusting circuit and a display device, which are capable of limiting a fluctuation of an output voltage (Vcom) in the within a small range, weakening a flicker phenomenon and enhancing a display quality of a liquid crystal display. The adjusting circuit for the output voltage (Vcom) comprises a voltage supplying module, a temperature sensing module and an adjustment outputting module, wherein, the voltage supplying module is connected with the temperature sensing module and the adjustment outputting module, and is configured to provide input voltages to the temperature sensing module and the adjustment outputting module; the temperature sensing module is connected with the adjustment outputting module, and is configured to convert a temperature sensed into an electric signal and transmit the same to the adjustment outputting module; and the adjustment outputting module is configured to adjust an output voltage (Vcom) according to the electric signal transmitted by the temperature sensing module, wherein the output voltage (Vcom) fluctuates between an upper limit voltage and a lower limit voltage which are preset.