In the motor control system, the rotor position signal is an important parameter to adjust the operation of the motor. Ordinary motor applies in the environments of high temperature and full of oil, which requires accurate position signal. The eddy current sensor is applied to motor position detection system due to its characteristic of simple structure, low cost, high temperature resistance to oil pollution and high reliability. Motor position detection system has a high demand for accuracy and sensitivity, eddy current sensor needs analysis and optimization design. In this paper, a new three-coil eddy current sensor is proposed. The eddy current sensor is analyzed by electromagnetic field correlation theory. The finite element method is used to analyze the new eddy current by using the ANSYS software and the APDL language. The data needed for the analysis are obtained, which provides a basis for further design of an eddy current sensor suitable for motor control system.