Differential protection provides a reliable and effective means for fast and accurate fault isolation of distribution lines. However, traditional optical fiber laying is difficult and operation and maintenance is expensive. This limits its application in a distribution network. This paper presents a design scheme of differential protection for distribution lines under wireless communication. The communication channel for differential protection is constructed by using the technology of a regional ad-hoc network, and information transmission does not depend on public network transmission equipment. Dynamic directional compensation technology is used to realize the accurate synchronization of data on each side, and it does not depend on the external synchronization equipment. A multi-level security strategy is adopted to strengthen network security and improve the security of the service data transmission and access. The anti-interference technology of wireless communication is adopted to avoid electromagnetic interference and ensure the reliability of data transmission. Having set up a test platform in the laboratory for system testing, the results show that the wireless channel based on the regional ad-hoc network has a short transmission delay, small delay jitter, high data transmission reliability. All performance indices of the channel and protection function meet the requirements of differential protection of distribution lines. The value of engineering application and potential popularization of the technology has been verified through trial operation. This work is supported by the Youth Fund of National Natural Science Foundation of China (No. 51507050) and Young Elite Scientists Sponsorship Program by CSEE (No. CSEE-YESS-2017).