As the primary protection of the 220~750 kV network strengthens, there are more controversy to relay coordination of backup protection in power industry. To solve the problem, this paper mainly introduces several common installation methods used in the field about backup relay coordination in high voltage power network, and analyzes the reasons of different relay coordination schemes. In view of grounding distance measuring impedance under the influence of zero sequence compensating coefficient, the special consideration in grounding distance protection setting is discussed. Furthermore, through the analysis of high voltage power network backup protection and verification of actual case, a setting calculation method used in high voltage system backup protection is recommended.