Abstract: The underground petroleum storage caverns needs reasonable design scheme.The layout and direction of caverns, shape and dimension of section, construction sequence and excavation methods will affect the optimum design and long-term stabilities of storage caverns in different extent and level.To fully exhibit the actual characters in the numerical simulation experiment of underground petroleum storage caverns design, it is presented in paper that the orthogonal experimental design is used to complete the optimum design of the caverns by numerical simulation, and the optimum layout and directions of the caverns, construction sequence are obtained.Meantime, the corresponding methods of calculation and analysis on the experiment index are established.