Abstract: The accuracy of jacking force calculation is crucial to the selection of supporting equipment in the pipe jacking construction of pipe roof, however, the existing calculation formula does not consider the influence of the lock on the jacking force of the jacking pipe. Relying on the example project of Guiqiao Road station, Shanghai Rail Transit Line 14, the design of lock of pipe roof is introduced. The mechanism of the effect of the lock on the jacking force is studied. The lock hinders integrity of the formation of mud screen and increases frictional resistance of the jacking. When the lock is squeezed through reinforcement zone, the reinforced soil undergoes plastic damage, which creates resistance to the lock through the reinforcement zone. The measured jacking forces of four types of jacking pipes, separate pipe, advanced pipe, socket pipe and closed pipe, are analyzed respectively, and the formula for calculating the jacking force of pipe roof with lock is proposed. The calculated results are in good agreement with the measured jacking force and can be applied to similar engineering jacking force calculations.