In order to understand the deformation law of Tunnel construction and set a reasonable reserved deformation based on it, the deformation law and reasonable reserved deformation under different surrounding rock levels are studied by using the Taibai Mountain Tunnel under construction as the project support through field measurement and statistical fitting analysis. The results show that: 1) The overall deformation of Taibai Mountain Tunnel shows the characteristics of significantly greater settlement than relative convergence; 2) The deformation law of the deep buried section of level V and the soft rock section of level IV are similar, and they have successively experienced three stages of rapid deformation, continuous growth and slow deformation; 3) The reserved deformation of the Grade V deep buried section is too small, and it is recommended that the reserved deformation be 150～230 mm . The reserved deformation of the Grade IV soft rock section is too large, and it is recommended that the reserved deformation be 30～70 mm . The results can provide a certain reference for tunnel construction in similar strata.