This disclosure provides a method and transceiver for a for a digital subscriber line (DSL) system. A first transceiver calculates a first table including a parameter of bit allocation for sub-carriers and transmits a switch message to a second transceiver connected thereto when a communication performance parameter reaches or exceeds the predetermined value; in response to the switch message, the second transceiver calculating a second table including a parameter of bit allocation for sub-carriers based on a calculation rule to keep the parameter of bit allocation within the second table as same as that within the first table, and the first transceiver communicates with the second transceiver using the first table and from a certain symbol to implement synchronous switch.