Conventional double side drift method has such disadvantages as complex construction sequence, low construction speed and long time for support ring forming. In this paper, the conventional double side drift method is optimized, and the construction safety of the optimized double side drift method is analyzed by means of numerical simulation, on basis of the engineering practice of Hongmianlu tunnel in Shenzhen. Conclusions drawn are as follows: 1) Optimized double side drift method is proposed; 2) When optimized double side drift method is used in proper geological conditions, the technical requirements for the ground surface settlement, structure forcing and construction safety can be met; 3) Optimized double side drift method can result in good technical and economical efficiency.