The large amount of access to the distributed power supply has gradually transformed the distribution network from the traditional unidirectional tidal radial network to the two-way tidal multi-terminal power supply distribution network, and a multi-segment line represented by T-type wiring has appeared. Based on the fault characteristics of various types of distributed power supplies, this paper analyzes the amplitude-phase relationship of multi-terminal currents in active distribution networks under short-circuit faults, and proposes a differential protection scheme based on multi-terminal current amplitude-phase relationship. The protection scheme includes the initiation criterion and the composite action criterion. The initiation criterion has the function of distinguishing the faults outside the zone. The action criterion is the logical sum of two independent criteria to ensure reliable action and avoid mis-operation. In addition, the article discusses multi-end information synchronization technology based on Fibre Channel communication for distribution network to realize multi-terminal information synchronization transmission. The simulation results of PSCAD/EMTDC show the reliability and quickness of the proposed scheme.