The invention relates to a dual computer hot-standby system of an LED display screen, which comprises two video distribution devices and m scanning card arrays. Each video distribution device is respectively connected with the m scanning card arrays, the received video data are decoded, accessed, recombined and packed and are respectively output to the m scanning card arrays through m paths of parallel interfaces; and each path of signals output by the video distribution devices is transmitted to n scanning cards forming the scanning card array, each scanning card intercepts data for setting regions of pixel points, and the data intercepted respectively are subjected to decoding, accessing, data processing and distribution and output to the LED display screen. By adopting two sets of separate data channels, the invention can realize heat switching of the system when some sets of data channels are in trouble, thereby the stability and the reliability of the system is improved and the ratio of manual maintenance is also greatly reduced.