Abstract: Lubricating oil film thickness is the key parameter for characterizing the lubrication state, which is essential for its accurate measurement. Facing the technical difficulties in the in-situ detection of the lubrication state of space bearings, a study on the eddy current detection method has been carried out, which aims to address the issue of lubrication oil film thickness measurement. In this paper, a finite element simulation model of the eddy current method for oil film thickness detection is established first based on the electromagnetic field, and the effects of basic coil parameters such as excitation frequency, number of turns, and diameter-to-height ratio on the detection performance, including sensitivity, are revealed. Then, the optimal values of coil parameters are proposed, according to the simulation results of the optimized detection model under the curved surface and relevant constraints, and the detection performance of the self-developed eddy current sensor is verified by a series of experimental tests Finally, a quantitative analysis is conducted to explore the influence of the curvature radius of the measured surface on the detection performance of the eddy current method, and the detection performance verification under the curved surface with a curvature radius ranging from 3 mm to 15 mm is completed. Meanwhile, the influence of the curvature radius of the measured surface on measurement deviation is revealed. The research work provides a necessary theoretical support for the development of eddy current detection technology in the field of high-precision detection of lubricating oil film thickness of space bearings.