The structure cut and convert (CC) method is a new type of undercutting method. The core idea of CC method is converting the mechanized excavated small crosssection structure into large crosssection underground space structure. In order to study the stress situation of structure constructed by CC method and realize safe and economic structure, the element structure and integral structure are designed and analyzed; the structural stress under 3 conditions is analyzed by taking a case study for example, and the bending moment, shearing force and axial force are obtained. The results show that: (1) The design results are safe and reliable, which can meet the engineering requirements. (2) The results can provide a new method and reference for analysis and design of underground structure constructed by CC method and similar projects in the future.