The purpose of the present paper is to describe the simulation of electrochemical drilling (ECD), which is generally affected by the electrical field and the flow field between two electrodes. A body-fitted transformation is applied to predict precisely the gradient of the electric potential field, and a bubbly-two-phase flow model is used to simulate the quasi-static electrochemical drilling process. The metal removal rate, determined by the variation of electric potential and the thermal-fluid properties, is then calculated. Numerical results agree well with experimental data. The void fraction is the most important factor in determining the electrolyte conductivity and the equilibrium shape of the workpiece. The overcut of the workpiece can be reduced by increasing the tool feed rate or decreasing the electrolyte flow flux. A bare bit type of tool, compared with coated tool and bare tool, can also diminish the overcut in ECD.