The present application provides a method and display apparatus for improving uniformity of displayed image, The method comprises inputting a first image signal to a display apparatus; compensating the first image signal in accordance with an image compensation data to obtain a third image signal, wherein the image compensation data is an amount of shift in a voltage of a common electrode of an array substrate of the display apparatus determined in accordance with a difference value between a grey level information of the first image signal and the grey level information of an original second image signal corresponding to the first image signal; and displaying the third image signal. Through the method above, the present invention effectively improves the uniformity of the displayed image without decreasing the displayed brightness of the image.