Using the finite element method, a three-dimensional model of cement-soil arch support structure considering the joint action of structure and soil is established, and the structure is numerically simulated and calculated. The analysis of the calculation results shows that the earth pressure behind the wall is between the static earth pressure and the Rankine earth pressure, and is distributed in a triangle along the vertical direction, between horizontal and radial uniform distribution along the horizontal direction, the earth pressure will be distributed along the horizontal and vertical directions after the support structure, the maximum load ratio shared by the horizontal arch is between 60%~70%, the cement soil arch is basically in the full-section compression state, the force mode of the arch foot pile above the excavation surface is similar to that of the cantilever pile, and the maximum bending moment of the whole length is at the excavation surface position.