The invention discloses a method for detecting the wall thickness of a metal pipeline by using an electromagnetic eddy current method. The method is characterized by through a phase unwrapping equation, carrying out phase unwrapping; then, calculating an error thetae between an unwrapped phase thetaan and a theoretical phase value thetath, and constructing a relational expression psi0 between themagnetic permeability mu and the electrical conductivity sigma of a metal pipeline wall; and then fitting; and finally, according to a fitting curve, calculating the wall thickness of the metal pipeline after simulation compensation.