In order to overcome the shortcomings of the traditional optimization method of the internal force of the suspender of the tied arch bridge，such as time-consuming，low accuracy，and complicated calculation，an improved CSO-ABC algorithm is proposed to optimize the internal force of the suspender of the tied-arch bridge with steel box arch-ribs. First，a hybrid CSO-ABC algorithm was established and the detection bee phase was improved，and three test functions were numerically tested to verify the accuracy and effectiveness of the algorithms. Then，taking the steel box tied-arch bridge as the engineering background，the finite element calculation of the CSO-ABC algorithm is carried out through the ABAQUS-Python script，and the automatic optimization of the internal force of the suspender based on the CSO-ABC algorithm is realized. The research results show that the improved CSO-ABC hybrid algorithm has the advantages of fast convergence and high precision compared with the independent CSO algorithm and ABC algorithm. The automatic iteration based on script greatly improves the efficiency of internal force optimization of the suspender. The maximum optimization range of the internal force is 2.17%. When the peak stress of the steel arch rib and the concrete girder increases by 4.9 MPa and 0.8 MPa，respectively，the peak displacement of the arch rib and the girder decreases by 12.7 mm and 12.1 mm，respectively. The optimized bridge state is very close to the original design. The algorithm can provide a reference for related construction，monitoring，and design work.