Based on practice engineering of pile-soil interaction induced by side-crossing tunneling, a simplified calculation method is proposed to evaluate the lateral displacement of the existing pile. The two-stage method is selected to get a simplified calculation method of the horizontal displacement of adjacent piles caused by shield tunneling. In the first stage, the Loganathan formula is applied to calculate the horizontal soil-free displacement at the pile axis caused by shield tunneling. In the second stage, the pile is simplified as an Euler-Bernoulli beam lying on the Vlasov foundation model, then the governing equation of horizontal displacement of the pile is established. After considering the boundary of the pile, the analysis of the mathematical matrix of tunneling on the adjacent pile is obtained by using a finite different method. Next, taking the soil blocking effect between pile groups into consideration, further, the difference solution for horizontal displacement of adjacent pile groups can be detected. By comparing with actual measurement in two engineering cases, the superiority of the proposed method can be verified. The parameters analysis of group piles shows that the horizontal displacement of adjacent pile groups increases with the increment of tunnel buried depth and ground loss ratio, but the depth of maximum displacement occurrences increases with the increase of the buried depth of the tunnel. The increase of the tunnel-pile horizontal distance causes the decrease of the horizontal displacement of the adjacent pile groups, but the rate of decrease slows gradually.