A compensation circuit, a control chip, and a display device are provided to solve a problem of low luminance of OLED display panels due to an existence of drifting of threshold voltage of the OLED display panels. The compensation circuit is applied to a drive circuit which includes a first TFT, a second TFT, an OLED, and a capacitance. The compensation circuit includes a third TFT and a detection circuit. A control electrode of the third TFT is configured to be connected with a second electrode of the second TFT, a first electrode of the third TFT is configured to be connected with a control electrode of the second TFT. The detection circuit is configured to be turned off and turned on respectively when receiving two continuous voltage signals output from the second electrode of the third TFT.