To provide base isolation design simplified method of LNG storage tank,combining base isolation engineering design requirement of LNG storage tanks, based on the response spectrum design theory, considering and not considering mass spring damping parameters 2 kinds of LNG storage tank simplified mechanical models were established. Seismic effect coefficient curve for the LNG tank response spectrum design and response spectrum basic steps of LNG storage tank base isolation were presented. Selecting 1.6×10⁵ m³ LNG tank response spectrum and time history analysis method supplementary checking, the results showed that: compared with the traditional structure, it could effectively reduce the base shear and the tank wall overturning moment,the simplified model was feasible based on response spectrum theory, the calculation results desirable time-history method average value and response spectrum method a larger value, tank design can only consider flexible impulse mass and the convective mass contribution to the base shear and tank wall overturning moment, the foundation design should consider all mass contribution to the base shear and base moment.