The present invention discloses a method for demolishing loop in multi-protocol label exchange. The method includes: if the current node senses color-line retrace event, to judge whether the upstreaminterface of the color line is detention state, if it is true to interdict the color line retrace information issued by the upstream interface; if not to issue color line retrace information by the upstream interface continuously and transmit label mapping; if the current node senses color line demolishing event, to clear the color line information of the upstream interface of the color line, andtojudge whether the node has received other color line of same business, if it is true to expand new color line on the downstream interface of the color line, if not to issue color line demolishing inf ormation on the downstream interface of the color line. By means of the solution of the present invention, to avoid establishing redundant LSP, at the same time, to ensure the other upstream node ofthe current node obtain retrace color line and label mapping information without dead angle, when there are other color lines which have same transmission equipollence class to the demolished color line.