The present invention discloses a method and a device for axial separation by the inner surface of a permanent magnetic arched groove, comprising: adsorbing materials to be selected that axially flow through the inner surface field strength and the gradient area of a rotating separation drum (2) by using the energy on the inner surface of a permanent magnetic arched groove (1); wherein materials with lower specific susceptibility pass through a selected material channel (13) and flow out of a low magnetic material outlet (9); materials with higher specific susceptibility are adsorbed on the rotating separation drum (2) and fall into a high magnetic material groove (7) under the action of its gravity; and materials with higher specific susceptibility flow through a high magnetic material outlet (8) and then are collected; thereby various materials with different specific susceptibilities can be separated.