In order to accurately calculate the axial compressive bearing capacity of ultra-high-strength concrete precast columns, a modified calculation method considering the restraint effect of stirrups is proposed. The restraint effect of stirrups on the concrete core is analyzed, and a modified calculation formula is derived. The proposed method is verified by comparing with the experimental results. The results show that the proposed method can accurately calculate the axial compressive bearing capacity of ultra-high-strength concrete precast columns.