The eddy current displacement sensor must be designed and analyzed so as to satisfy the high precision requirement of position detection in magnetic suspending flywheel system.The relationship between impedance and detected distance can be obtained based on the theory of eddy current by using the 2D model set up by utilizing the Ansys software.The measuring circuit’s output voltage peak value influenced by distance change can be obtained by emulate result.According to the parameters of coil model and element in the circuit

the reality sensor coil detecting loop can be made.The consistency of experimental result and emulating result indicates that the finite element method is valuable for design of eddy current sensor coil.