The working principle and characteristics of eddy current detector is introduced in this paper, and in order to resolve the problem of contact collision existed in this system, the part simulation method is used by means of ADAMS & RecurDyn which based on the virtual technique about dynamic simulation model and the usage of interpolating spline to carry out data deliver between kinds of software, and the design of the virtual machine is completed. Then according to the simulation results, the simplified model of principal axis and bearings are set up, and the neutral phenomenon between the running main shaft and the probe to avoid the lift-off effect is analyzed. Meanwhile, the simulation of the whole equipment's working state is carried out, and the coordination of each system operation is observed. Currently, this detector has already put into the usage and obtained a good result.