Aiming at the operation safety of LNG plants equipment, this research started with analyzing comprehensively the factors affecting equipment operation safety. On this basis, this research briefly introduced the SEM (Structural Equation Modeling), and conducted a comprehensive research on the factors affecting equipment operation safety in LNG plants by building up the SEM, making use of relationship assumptions. It laid the foundation for the development of equipment operation safety measures for LNG plants. Research results show that during the operation of LNG equipment, factors such as staff, environment, equipment operating status, equipment management factors, and outsiders will have an important impact on the safety of equipment operation. Among them, staff, environment, equipment operating status and equipment management have a positive and significant impact on its safety. Compared with other factors, the impact of staff is not very obvious. For outsiders in the factory, safety has a greater impact on outsiders than the outsiders impact on safety. The results of this research are conducive to improving the equipment safety evaluation system of LNG plants, and are conducive to the development of relevant measures for LNG plants to ensure the safe operation of equipment.