The present invention discloses a method for self-routing in synchronous digital cross-connection, comprising: self-routing transmitting means insert a CM data into a STM-N data stream according to a frame header indicator and a self-routing start address signal; self-routing receiving means extract the CM data from the STM-N data stream according to the frame header indicator and the self-routing start address signal, and write the CM data into a cross-connection control memory. The present invention also discloses a system for self-routing in synchronous digital cross-connection, comprising: self-routing transmitting means and self-routing receiving means, wherein, the self-routing transmitting means comprise a self-routing transmitting control unit, a first CRC checking unit and an inserting data generating unit, the self-routing receiving means comprise a self-routing extracting control unit, a second CRC checking unit and a cross-connection control memory. The present invention provides users with a self-routing scheme for synchronous digital cross-connection, which can be realized with ease, occupies less resource, has better reliability and is suitable for large capacity cross configuration.