Optical fiber differential protection is widely used as the primary protection of power transmission line, but it may be influenced by extreme natural and man-made hazard which would impair protection performance. This paper discusses a technical scheme of pilot differential protection channel based on wireless sensor network. Taking the number of nodes and failure rates into account, redundancy arrangement of nodes based on reliability of the whole communication network and optimal cost is proposed. Besides, this paper studies the influence of the communication distance, line spans and communication range of nodes on end-to-end time delay under AODV routine. The results of pilot differential digital simulation test shows that emergency protection channel constructed by wireless sensor network which uses redundancy arrangement method to do network panning can achieve strong survivability and meet the need of pilot differential protection under extreme disaster. This work is supported by National High-tech R & D Program of China (863 Program) (No. 2015AA050201).