Shield construction method for crossing existing building

The invention relates to a shield construction method for crossing an existing building, which comprises the following steps of: establishing a pre-estimation model, simulating and predicting shield construction by utilizing the pre-estimation model according to a construction drawing, and modifying a construction scheme according to a simulation result; shield tunneling is utilized, the excavation face pressure of a slurry shield is set according to construction parameters, the shield tail gap and the tunneling speed of the shield are controlled, and the pressure and flow of synchronous grouting are controlled; and the settlement amount of the stratum is analyzed through the pre-estimation model and the construction parameters, and secondary grouting and reinforcement are conducted according to the settlement amount. The problem that shield control is difficult under the working conditions of large gradient, small curvature and soft soil is effectively solved, the shield is accurately controlled, so that the