To elucidate the variations in non-limit state earth pressure for limited soils mass under the rotation at the top of a rigid retaining wall (RT) mode, and to address the incomplete consideration of wall displacement, horizontal shear stress, and other influencing factors in existing earth pressure calculation methods, a numerical calculation method for passive earth pressure of a finite soil mass was developed within the framework of the differential element method. This method integrates considerations of wall displacement, soil strength parameters (c_m - φ_m), soil arching effects, and the impact of horizontal shear stress. By combining triaxial unloading tests and stress Mohr circles, the relationship between soil strength parameters (c_m -φ_m) under non-limit states and wall displacement was derived. Based on the principles of soil arching effect, stress analysis of the finite soil body was conducted, and static equilibrium equations for differential soil elements were established, further creating a numerical iterative format for passive earth pressure within a depth range. The proposed method was validated for its rationality and accuracy through comparisons with existing research. The results show that the lateral constraints under the RT mode help enhance the soil s shear resistance; Non-linear distribution of passive earth pressures along depth in finite soils; the magnitude of earth pressure decreases with a reduction in soil strength parameters (c_m - φ_m), a decrease in the initial slip surface angle, a reduction in the bottom of wall displacement ratio, and an increase in the width-to-depth ratio. The method of this paper can provide theoretical guidance for the economic design of retaining structures in practical engineering.