Abstract: In order to ensure the safety of LNG storage tank during operation, the optimization method of structural safety of LNG full-capacity storage tank under explosion load was studied. The finite element model for tank explosion analysis, which had taken into account the liquid sloshing in the tank, was established and the sloshing state of LNG was simulated by the impact and convection spring-mass model. The time-history analysis of the storage tank was conducted to determine the dynamic response of the storage tank structure. The M-N curve was used to analyze the safety of the storage tank, the solutions were proposed for the situations that did not meet the safety requirements, and the anti-explosion capability of LNG full-capacity tank was optimized. The results show that the structural response of LNG full-capacity tank appears as a periodic attenuation under the explosion load. The main impact area of explosion is located at the joining between the tank dome and the outer wall, and the impact on circumferential safety is greater than that on radial safety. Both reducing the peak pressure of explosion load and increasing the reinforcement of components can effectively improve the safety of full-capacity storage tank.