Developing a facile approach based on transition metal-based Prussian blue (PB) and its analogues (PBAs) with core-shell nanostructure is a very promising choice for constructing cost-effective electrocatalysts for oxygen evolution reaction (OER).Herein,a bimetallic core-shell structure with open cages of Fe-doped CoP (Fe-CoP cage) has been synthesized using CoFe-PBA cage-4 as precursor through a facile hydrothermal method and following phosphating process.Interestingly,there is an open hole in each face center of Fe-CoP cage,which suggests the more exposure of active sites for OER.Electrochemical measurements show that Fe-CoP cage can afford a current density of 10 mA cm-2 at a low overpotential (300 mV),which is better than that of RuO2.The excellent performance can be attributed to Fe doping composition and unique open-cage core-shell structure.The synergistic effect derived from bimetallic active for OER has been discussed.And its great catalytic stability has been evaluated via 1000 cycles of CV and chronoamperometry measurement.This work provides a potential method to design multiple transitional metal-doping electrocatalysts with complex framework derived from PBAs for water splitting.