To analyze the mutual influence of adjacent twin-bore tunnel’s construction, complex function and Schwarz alternation method were used to solve the analytical function of ground displacement based on the gravity effect of soil layers and the convergent deformation of tunnel chamber, and the ground displacement was corrected by setting displacement constraints, so that an analytical model of adjacent twin-bore tunnel under the gravity effect of soil layers was finally obtained. Based on the model mentioned above, this study analyzed the influence of iteration number, displacement binding, and horizontal chamber deformation on the strata displacement, and the results shows that the calculation meets the accuracy requirements with iteration number of 2. It should be noted that by comparing the results corrected by displacement with those without the displacement correction, setting the boundary condition of vertical displacement makes the relative displacement curve of ground surface shifted downward as a whole, and the left horizontal displacement boundary condition can make horizontal deformation shift leftward at a certain amount. With the increase of chamber’s horizontal deformation coefficient, the relative vertical deformation of strata will increase while the relative horizontal deformation will decrease, and the effects on them are different. Based on the criterion of ground displacement, the strong, weak and no influence zones of the twin-core tunnel with geometric proximity and buried depth ratio are obtained.