For increasing the efficiency of previous whole network traversal current limiting project, a current limiting strategy by adjusting power grid configuration based on improved REI equivalence is proposed for large-scale power system. It combines the network equivalence technology with current limiting mechanism by adjusting 500 kV power system configuration and carries out a pretreatment to primary system according to the branch current limiting sensitivity index. Original system is divided into research system and several external subsystems. The subsystems are simplified using improved dynamic REI equivalence method, and the parameters of the equivalent generator are calculated according to power transfer distribution factors of each generator on virtual branch during equivalence. The simulation results of two cases show that the improved REI equivalence method can better preserve the dynamic characteristics of the original system and quickly select the optimal breaking lines. This work is supported by National Natural Science Foundation of China (No. 51577077 and No. 51477090).