Walls of the LNG storage tank are mainly built by the prestressed concrete, but the material of prestressed concrete is complex nonlinear materials. The characterized of concrete is that it can bear very big pressure, but cannot bear the pull. The LNG storage tank is a typical pressure vessel; it has a great significance to research the stress distribution and the cracks of the wall of concrete. In this article, using the ADINA numerical simulation software to establish separate model of reinforced concrete, and research the cracks and the failure modes of the concrete in the normal using state and leakage state by using the stress contour of prestressed steel and ordinary steel and concrete crack map of external wall. Identify the most dangerous place of the storage tanks in several of state. It can provide theoretical basis for domestically independent design and construct LNG storage tank in the future, and then provide domestic reference for crack treatment of LNG storage tank.