Embodiments of the present invention provide a method and a device for line-switching in an automated main distribution frame (AMDF) which may solve the problem of contact point damage which may occur during hot switching of micro electromechanical system (MEMS) matrix, and further solve the corresponding problems which may occur during the line-switching in AMDF. In particular, the present invention is preferably embodied in the following way: when switching operation of a switch unit in MEMS is to be performed, the current introduced into MEMS matrix is firstly cut off, and is then recovered when the switching operation is finished, so as to prevent the “agglutinate” phenomena. Therefore, the present invention provides corresponding protection for the switching process of MEMS matrix relays in AMDF, and effectively prevents the “agglutinate” phenomena when the switch unit in MEMS matrix performs switching operation, whereby the reliability of AMDF is enhanced.