The present invention provides a peer-to-peer distributed system and a method for adding a node in the peer-to-peer distributed system. According to the method for adding the node in the peer-to-peer distributed system, a source server node parallelly synchronizes write operation to a newly added node when performing data transfer on the newly added node, and therefore, the problem of long consumed time caused by a condition that write operation can be synchronized only after data transfer is completed can be solved, and data access and traverse operation can be better supported in a route change process.