Abstract: Two methods for mutual verification calculation of simplified model and fluid solid coupling model are used in the stress analysis of the large storage tank. The calculation for pulsed liquid quality M₀, the height of gravity of pulsed liquid H₀, the height of gravity of liquid convection H₁, and the equivalent stiffness k₁ of spring simulating slosh frequency of liquid convection is based on HOUSNER theory and as the input parameters of finite element model. FLUID80 elements are used in the fluid solid coupling model to model the fluid and SHELL181 elements to model the storage tank. Fluid solid coupling model considering the structure damp is used to calculate the response of the tank under seismic time history.