While the surface of integral impeller blade was electrochemically machined, cathode cannot rotate in accordance with other movement axes, which results in nonuniformity in velocity of electrolyte and normal direction of the machining blade surface, thereby causing inaccuracy in the machined blade surface. In order to solve this problem, the shaping law was studied in Electrochemical Finish Machining. Then relative positions between cathode slot and blade surface were analyzed during the process of Electrochemical Machining (ECM). Three parameters, namely feed direction, feed velocity and initial machining inter-electrode gap, were adjusted to conduct the fundamental experiments when direction of cathode slot was changed. Afterwards machining accuracy as well as surface quality of workpiece was analyzed. Finally according to experimental results, direction of cathode slot was determined practically in electrochemical machining process and the integral impeller blades meeting the requirement were electrochemically machined.