The aim of the study is to develop a measuring and presetting system for tool electrodes used for machining rimmed turbine blisks. A data-sampling method based on voltage monitoring was established as the foundation of this study. The proposed system, which consisted of three parts (mechanical, electric control and computer numerical control system software), was then realized. The method for extracting characteristic points from the theoretical model of the tool electrode and the bicubic B-spline algorithms for reconstructing the actual model of the tool electrode were established. A simulation analysis of the surface deviation was conducted to verify the extracting method and the algorithms. Next, a suitable accuracy evaluation method was developed to evaluate the accuracy of the tool electrode. Several experiments were performed to verify the performance of the system. Currently, the system is applied to practical production and has shown satisfactory results.