The disclosure discloses a display panel, a voltage adjustment method thereof, and a display device, and the display panel includes: at least two reference sub-pixels; a voltage compensation element coupled respectively with respective reference sub-pixels; and a power management element coupled with the voltage compensation element, wherein the voltage compensation element is configured to acquire valid values of pixel voltage of the respective reference sub-pixels when the at least two reference sub-pixels receive the same data voltage, and to generate a compensation signal of gate off voltage for the purpose of making the acquired valid values of the pixel voltage of the respective reference sub-pixels uniform; and the power management element is configured to adjust a voltage value of the gate off voltage according to the compensation signal of the gate off voltage.