Abstract: The traditional underground excavation method has problems such as high risk, low efficiency, great impact on the surrounding environments and large investment. It is difficult to construct large underground structures in soft strata or complex environments. In order to solve these problems, a new underground excavation method based on the large rigidity support system is proposed. The pipe roof, horizontal beam and vertical column are used to construct a large rigidity support system, and each component is constructed by using the non-excavation method or constructed in a small space under the protection of pipe roof, which ensures the construction safety and prevents the stress release of the stratum. After the support system is constructed, bulk excavation can be carried out. The new underground excavation method has the advantages of simple process, high efficiency, low risk, small impact on the surrounding environments and small investment. Numerical analysis and engineering examples verify the feasibility and practicability of the new method, which provides a new idea for the construction of large underground structures.