Theoretical calculation is made on the reinforcement scope of the end soil of Shunyulu power tunnel by means of elastic plate uniform load model, idealized sliding instability model and soil disturbance balancing theory. The calculation results show that the longitudinal reinforcement length of the launching section specified in the design is smaller than the theoretical value. Therefore, simulation is made on shield launching so as to verify the safety under the condition of the designed reinforcement scope. The simulation results show that the safety index is within the permission scope, the launching is safe and the design is proper.