The inverter interfaced distributed generator (IIDG) on distribution network is modeled to analyze its fault characteristics, therefore, the relay protection scheme of active distribution network considering low voltage ride through (LVRT) strategy is proposed in this paper. Fault analysis model of IIDG with LVRT strategy is established, and fault analysis methods suitable for active distribution network are proposed. A distributed protection scheme based on current amplitude and phase condition is proposed for an active distribution network with current measurement capability only. The fault characteristics of the line are analyzed in the amplitude-phase plane, and the fault position is determined by studying the different characteristics of the current amplitude and phase on the fault line and the non-fault line. On this basis, an improved criterion is proposed, which can improve the performance of protection criterion. This scheme can solve the contradiction between phase shift error and criterion sensitivity of traditional current differential protection, and the distribution network only needs the measuring capacity of current flow, which has certain engineering value.