For distribution networks with high-permeability Distributed Generation (DG), this paper proposes a novel integrated current amplitude protection principle by comparing the two ends of the line full phase current amplitude and positive sequence fault current amplitude which achieves low-cost and high-reliability compatibility. The model of 10 kV active distribution network is built by PSCAD to comprehensively simulate the influence of different DG permeability, fault location, fault type, transition resistance, asynchronous data and other factors on the protection principle. After theoretical analysis and simulation, it is proved that the scheme can accurately solve the fault location problems, the data used is simple, the resistance to transition resistance is excellent, the protection configuration is low, and the ability of resisting synchronization error is strong. This work is supported by National Natural Science Foundation of China (No. 51377100) and Science and Technology Project of State Grid Shandong Electric Power Company (No. 52061216000M).