Abstract: This article aims at the design of the control system of laser melting metal additive manufacturing equipment in selected areas, and strives to improve the stability and reliability of the operation of metal additive manufacturing equipment. By optimizing the control system architecture and designing a structured communication protocol, we designed a SLM metal additive manufacturing equipment control system based on the QT+PLC+RTC platform. And focusing on the coordination and control of peripheral equipment, such as lasers, galvanometers, and motor controllers, we had implemented a highly reliable control system for the metal additive manufacturing equipment with following features, self-controllable in the complete printing process, multi-threaded and coordinated, with a set of friendly human-computer interfaces.