Abstract: Based on the prototype monitoring of the separated reinforced soil abutment project of Mingchao Expressway, the numerical model of the bridge abutment was established by FLAC^2D software, and the force and deformation of the bridge abutment obtained from numerical simulation were compared and verified with the prototype monitoring results of the bridge abutment. Considering the correlation among filler type, compaction process and filler mechanical properties, the influence of the filler internal friction angle on the working performance of the reinforced soil abutment was simulated and analyzed. The results show that with the increasing of filler internal friction angle, the horizontal earth pressure and vertical earth pressure of the detached bridge abutment are reduced, and the vertical displacement, the horizontal displacement and the reinforcement strain are also reduced. When the filler internal friction angle is increased to a certain degree, the optimization effect on the bearing performance is decreased. When the reinforced soil filler in the project is selected, the filler internal friction angle should be determined according to the construction conditions on the site, and the performance and economic benefit should be weighed to make reasonable choice.