Aiming at the problem of arc extinguishing of HVDC relay, this paper presents an optimal design of electromagnetic system based on orthogonal test. In order to improve the breaking speed of the contact, a three-dimensional finite element model of the relay electromagnetic system is established. The key parameters of the electromagnetic system performance are analyzed, the optimization variables are determined, and the simulation model is verified by dynamic characteristic experiment. On this basis, the orthogonal test method is used to optimize the electromagnetic system of relay. The results show that the optimal design can improve the breaking speed of the relay contact and lay a theoretical foundation for improving the life of the relay.