This invention presents a multimode xDSL line card adaptive activation method, comprising the following steps: A) A master controller is installed and configured with multiple templates based on the modes of operation supported by a line card, and forwards templates to said line card; B) The line card receives templates forwarded by the master controller and activates the line card communications chip; C) The communications chip communicates with the remote CPE and decides on a mode of operation according to a handshake protocol; D) The line card employs a corresponding template according to the mode of operation chosen in Step C, and practices circuit activation with the CPE. This invention solves the existing problems in current multimode xDSL technology of poor compatibility and inability to adapt effectively.