Abstract: On the basis of the traditional calculation theory of soil pressure, this paper modifies the traditional cal? culation formula of soil pressure by defining related influence coefficients such as the tunnel width, section type, filling property, slope angle/ trench width, and proposes a calculating formula for the vertical soil pressure on the top of a high-filled open cut tunnel under considering these four influence coefficients. Firstly, the uneven soil pressures are transformed into uniformly distributed loads through the equivalent load method, the mathematical expression of the regression curve of vertical soil pressure on the top of the high-filled open cut tunnel is determined through the mathematical regression method and numerical simulation method, and the change law of the influence coefficients with H/W (the ratio of filling height to tunnel width) is analyzed, obtaining the influence degree and trend of the influence coefficients on the vertical soil pressure on the top of the high-filled open cut tunnel, so as to determine the calculating formula for the vertical soil pressure on the top of the tunnel. Then the established formula is verified by selecting two design conditions of railway open cut tunnels, and the results show that the average relative error between the calculation results by the proposed formula and the numerical simulation results is 1.68%, which verifies the correctness of the formula.