A method of monitoring the operation of an LED display screen, comprising the following steps of: - transmitting to the LED display screen via the video controller by the computer apparatus a geometric video image that reflects a physical dimension of the LED display screen, the display screen comprising a plurality of LED modules; - shooting a geometric image of the geometric video image displayed on the LED display screen by the video camera, - transmitting the geometric image back to the computer apparatus, - acquiring and storing coordinate information reflected in the geometric video image and the geometric image by the computer apparatus according to the transmitted geometric video image and the shot geometric image; and thereafter the following steps of: - transmitting two monitoring video images to the LED display screen via the video controller by the computer apparatus respectively, wherein black and white colors of the two monitoring video images are complementary to each other; - shooting two corresponding monitoring images by the video camera; - transmitting the two monitoring images back to the computer apparatus in order to store the two monitoring images; - computing absolute values of differences in color and luminance of each corresponding pixel between the two monitoring images by the computer apparatus to obtain a new composite image; - normalizing the composite image into a resultant image consistent with the LED display screen according to the coordinate information; and - determining a working status of each of the modules in the LED display screen according to a status and a position of each of the pixels in the resultant image by the computer apparatus. - transmitting to the LED display screen via the video controller by the computer apparatus a geometric video image that reflects a physical dimension of the LED display screen, the display screen comprising a plurality of LED modules; - shooting a geometric image of the geometric video image displayed on the LED display screen by the video camera, - transmitting the geometric image back to the computer apparatus, - acquiring and storing coordinate information reflected in the geometric video image and the geometric image by the computer apparatus according to the transmitted geometric video image and the shot geometric image; and - transmitting two monitoring video images to the LED display screen via the video controller by the computer apparatus respectively, wherein black and white colors of the two monitoring video images are complementary to each other; - shooting two corresponding monitoring images by the video camera; - transmitting the two monitoring images back to the computer apparatus in order to store the two monitoring images; - computing absolute values of differences in color and luminance of each corresponding pixel between the two monitoring images by the computer apparatus to obtain a new composite image; - normalizing the composite image into a resultant image consistent with the LED display screen according to the coordinate information; and - determining a working status of each of the modules in the LED display screen according to a status and a position of each of the pixels in the resultant image by the computer apparatus.