According to the wireless power technology using in the project, it is normally that a mathematical model of serious eddy current loss coupling structure of primary and secondary coil is passed through by metal shaft in the working environment. Establishing a transport model of electromagnetic coupling wireless power supply system，the analytical expressions of eddy current loss is deduced by solving Maxwell’s equations，analyze the eddy current losses in the system work eddy current loss characteristics combined with electromagnetic coupling model and eddy current losses in metal medium model. To verify the theoretical results, utilize Maxwell electromagnetic simulation software to analyze eddy characteristics，combined by the final experiment described ferrite magnetic shielding material for suppressing the effect of eddy current loss in metal environment.