Protection in distribution has been a difficult problem for a long time, because distribution lines are relatively shorter in distribution system and there are more cascade switches than the electrical transmission system. Based on the peer-to-peer communication system, a new protection theory for the multiple power and loop connection structure is brought forward in this paper. It ensures the switch action correctly when any fault occurs on the line and fulfills high-speed and reliable action. This scheme has been used in Guangzhou. Foshan, etc. And it achieves good effect.