A threedimensional detailed finite element model of threering segment lining structure is established by numerical analysis method. The influence of freezing excavation of foundation pit above the metro shield tunnel on the opening of circumferential joints and longitudinal joints of shield tunnel is studied; and the causes for water leakage of circumferential joints are analyzed. The results show that: 1) The opening of the longitudinal and circumferential joints and bolt stress increases with the freezing temperature decrease. 2) The maximum opening of the circumferential joints is 4.2 times the longitudinal one under the interaction of soil load and freezing temperature. 3) The friction caused by rubber gasket and joint groove is less than water pressure because the opening of the circumferential joints is the main cause that results in the water leakage of tunnel.