The invention relates to an automatic sorting method used for dismounting back a narrow-band carrier wave module of a concentrator. An automatic sorting device is composed of a module separating robotand a module separating multifunctional assembly, wherein an operating end of the module separating robot is equipped with the module separating multifunctional assembly; the module separating multifunctional assembly comprises a module take and place assembly, a positioning CCD camera and transfer box take and place assemblies; the end part of a working arm of the module separating robot is connected to one end of a supporting rod; the other end of the supporting rod is equipped with the module take and place assembly; the lower end of the middle part of the supporting rod is fixedly equipped with a stand column perpendicularly; the lower end of the stand column is fixedly arranged at the upper end of the middle part of a transverse plate; the lower end of the middle part of the transverse plate is equipped with the positioning CCD camera; and the lower ends of the two sides of the transverse plate at the two sides of the positioning CCD camera are symmetrically equipped with the transfer box take and place assemblies. The automatic sorting method realizes automatic separation for NG modules after the modules are detected, and automatic storage for qualified modules, reduces artificial participation in a module detecting process, and improves module detecting efficiency.