Abstract: With a ± 800 kV transmission line as an example,considering the spacing changes of sub-conductors on the influence of electromagnetic force and the collision process,a dynamic finite element calculation model of a 6 split conductor spacers’ centripetal force dynamic finite is established in this paper. The fourth order Runge Kutta algorithm is put forward to solve the model,and the conductor displacement of each node and the change of spacers’ centripetal force under short circuit condition are analyzed. Based on the calculation results,the influence of short-circuit current on the moving process of the sub-conductor and the dynamic change of the spacer’s centripetal force are analyzed. And the calculation results are compared with the results of traditional Manuzio formula.