Electrochemical machining is one of the main machining methods for turbine blades of aerospace engine core component. The cathode design method and correction of blade electrochemical machining tools are the key to improve the accuracy of blade electrochemical machining. In electrochemical machining, the standardization and uniformity of the cathode feed angle, the workpiece clamping angle and workpiece profile normal direction angle are important factors affecting the accuracy of the cathode design. The threedimensional model structure of turbine rotor blade of a small engine was analyzed, the distribution law model of machining gap between cathode tool profiles corresponding to each sampling point on blade profile was established. The cathode feeding angle and the blank clamping angle were optimized, combined with the electric field simulation analysis, and the cathode profile model design method of electrolytic machining was studied to improve the cathode profile design accuracy.