Abstract: Multiple new energy connected to the grid, causing the anti-island protection device false detection, which leads to the problem of protection failure. This paper takes HS substationg in Hohhot as an example, in which the small photovoltaic power supply is connected to one side power supply. By analyzing the operation logic of anti-island protection and automatic protection device, adding measured electrical data of protection, proposing the solution of the protection action coordination optimization scheme based on the existing system, to ensure the automatic device reliable operation, prevent the island operation, and further improve the system power supply reliability.