Abstract: Objective: To optimize the conventional construction method of ′vertical shaft underground excavation + shield tunneling with forward thrust′ for metro engineering crossing ground fissure sections in Xi’an, an excavation scheme based on the new construction technique of ′shield tunneling followed by expansion′(abbreviated as STFE) is studied. Method: Based on the protection and control project of Xi’an Metro Line 15 Fujunmiaocun Sta. to Zhucun Sta. (FuZhu) interval tunnel that crosses F9 and F′9 two ground fissure belts, a pilot application of the new construction technique is conducted. The basic process and design principles of the STFE method are introduced. Six shield tunnel expansion excavation schemes for the control section are proposed by focusing on the feasibility, advantages and disadvantages of each scheme. Taking into account construction convenience, land subsidence control, and structural stress behavior, a recommended scheme is presented. Result & Conclusion: The STFE method eliminates the amount of vertical shafts and the reinforcement soil mass at tunnel ends, ensuring continuous shield tunneling operation, and solving the problem of limited ground operation conditions in control sections. Thus, the expansion excavation crosssection can be significantly reduced without considering forward thrust, thereby reducing engineering costs. During shield tunnel expansion excavation in the control sections, lateral and vertical supports can improve tunnel support structure deformation. However, the role of temporary invert arches or horizontal struts is relatively limited, and it is not substantial for setting under the conditions of guaranteed ground dewatering measures. Vertical struts can significantly improve the stress conditions of the expansion excavated tunnel supporting structure and should be retained. Considering the construction disturbance problems caused by cutting sections with lateral and vertical support, the ′full section + double vertical struts expansion excavation′ is recommended for the project.