Abstract: The paper introduced a mine-used LED display system based on CPLD and single-chip microcomputer,introduced design of overall,data processing unit of single-chip microcomputer and CPLD scanning and display unit of the system in details.The system takes 89C55 single-chip microcomputer as controller and realizes communication with PC and data processing function,and uses CPLD to realize function of automatic scanning of LED screen which simplifies the system structure and improves the scanning speed.