电化学加工（Electro chemical machining，缩写：ECM）是在电解液中利用金属工件作阳极所发生的电化学溶蚀进行加工的方法，利用单纯的电解作用的称电解加工。

是非传统加工方法，用来加工极硬材料或者传统方法难以加工的材料；而限制是加工物必须可导电；ECM可以切小角度或者奇异形状的角度。

加工时，刀具是阴极，加工物是阳极；低电压、高电流下进行电解，使电解液在压力下高速循环流过电极和加工物，刀具沿着欲加工的路径加工，没有和加工物接触，没有电火花产生；加工过程中，工件被溶解，是电镀的反向操作。

Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. It is normally used for mass production and is used for working extremely hard materials or materials that are difficult to machine using conventional methods. Its use is limited to electrically conductive materials. ECM can cut small or odd-shaped angles, intricate contours or cavities in hard and exotic metals, such as titanium aluminides, Inconel, Waspaloy, and high nickel, cobalt, and rhenium alloys. Both external and internal geometries can be machined.