Soil around the cylindrical pore is divided into elastic and plastic regions. In the elastic region, the small deformation theory is applied while in the plastic region, the large deformation theory and unified strength criterion are applied. According to the stress equilibrium equation and the boundary condition of continuous stress and deformation, the theoretical solution to plastic region radius, limit expansion pore pressure excess pore pressure and excess pore water pressure of the cylindrical cavity expansion can be derived when considering large deformation and non-drainage problems. Compared to the theoretical results of Cao L.F., the theoretical calculation results are closer to the field test results which show that the theory has a certain value in engineering application. Through calculations and analysis, it is also derived that expansion pore pressure increase is non-linear with the increase of b value, while the excess pore water pressure is just the opposite.