The surface settlement (SS) induced by shield tunneling method can be predicted using the modified Peck formula based on the modified gap parameters proposed in this work. The modified gap parameters considered shield tunneling parameters (STPs) can be expressed with the support pressure ratio of shield (λ), fill rate of grouting (β), and eccentricity ratio of shield (κ). Based on the actual cases of the Xi’an subway line 2 in China, the results of sensitivity and back analysis of STPs show that β has a minimal effect on SS, λ has a significant influence on SS, and κ has the maximum effect on SS. The maximum SS and surface curvature due to shield tunneling are be considered to control the permitted deformation according to the Chinese standards. Thus the control standards of STPs are obtained and suggested through the back analysis of damage classification by using the modified Peck formula.