In order to seek a kind of tank structure which can absorb shock and reduce costs， a new structure system of isolation tank is proposed. The restoring force model of rolling isolation is deduced by the principle of balances of forces， and the restoring force model of composite rolling isolation device is obtained. Based on the three-particle model and site soil model， the simplified mechanical model and motion equations of the new isolation tank considering soil-tank-liquid interaction （STLI） are proposed， and the seismic responses of seismic tank and new isolation tank that considered STLI and Non-STLI are studied under different sites. The results show that the new isolation tank can effectively reduce the base shear and overturning moment， but the control of the sloshing wave height is limited. It is suggested that in the high intensity area， under the premise of meeting the shaking wave height， the new isolation tank can be designed to reduce the intensity. After considering the STLI effect， the base shear and over? turning moment of seismic tank decrease obviously. The discrepancy rate gradually increases from class Ⅰ site to class Ⅳ site， and the decrease is most significant in soft soil. The seismic responses of the new isolation tank are less affected by the STLI， which can effectively cut off the coupling between the superstructure and the site soil， and weaken the influence of the STLI effect on the superstructure.