A display device and a display method thereof are provided. An image compensation unit is utilized to analyze a first image signal and a second panel data to calculate a difference value between a row number of first virtual rows included in the first image signal and a row number of second virtual rows included in the second panel data. Further, the first image signal is compensated to obtain a third display signal to display on the display panel, which can improve a display abnormality problem that occurs when the display panel is matched with an image input module from different manufacturers.