The invention relates to a ferromagnetic conductor relative permeability detection method and a ferromagnetic conductor relative permeability detection system based on skin effect. The ferromagnetic conductor relative permeability detection method is characterized in that a low frequency resistance value R0 between any two detection points of a cylindrical to-be-detected sample having a radius r is detected, and the distance between the two detection points is L; the resistivity Rho of the to-be-detected sample is calculated according to the low frequency resistance value R0 between any two detection points of the to-be-detected sample, the distance L between the two detection points, and the radius r of the to-be-detected sample, and the high frequency resistance value R between the two detection points of the to-be-detected sample is detected; the relative permeability (mu)r of the to-be-detected sample is calculated according to the low frequency resistance value R0 between any two detection points of the to-be-detected sample, the high frequency resistance value R, the radius r, and the resistivity Rho. The troubles of the prior art that the sample is required to be processed to be in the shape of a ring, and is required to be wound into the coil are prevented, and the defect of the magnetic leakage of the magnetic circuit is prevented, and therefore the system and the method are simple and smart, the detection result is accurate, the fast and lossless accurate measurement is realized, and the good application prospect is provided.