At present

there is a large-scale construction of salt rock storage groups in China. Many optimizable factors exist in the planning and design phase with different influencing magnitudes. The three main factors

i.e. the geometric distribution of ellipsoidal caves

the width of pillars and the position of the interlayer

are selected to be studied. The purpose of the research is to analyze the influence degree of the three factors and to determine the optimal storage group form. Three levels are set for each factor and nine text schemes are made based on the principle of orthogonal experimental design; and the related numerical simulation experiments are conducted. The improved experimental index of displacement and stress is chosen to evaluate laminated salt rock storage group. Using extreme difference analysis and variance analysis

the test results are analyzed in detail. The research results show: among the three factors

the position of the interlayer has the most significant influence

the width of pillars is in the second place and the geometric distribution of ellipsoidal caves is the third. The optimal storage group form: the angle of the adjacent caves is 60°

the width of pillars is 2.0D and the interlayer is distributed in upper 1/4H of the cavity.