An electronic device and a display image compensation method thereof are provided. The display image compensation method includes: receiving a first image signal and a second image signal sequentially at different time points, and displaying the first image signal by using a display unit; calculating current temperature information according to a display time length of the first image signal on the display unit and pixel data of the first image signal, and calculating a variation between the current temperature information and reference temperature information; and generating pixel compensation data corresponding to the current temperature information when the variation is greater than a preset value, compensating the second image signal according to the pixel compensation data, and outputting the compensated second image signal to the display unit.