The disclosure discloses a method for synchronizing network nodes in a time division duplex system. The method includes that: a network node acquires the cell identity information of other network nodes, and inquires the synchronization status information of the other network nodes from a synchronization information node according to the cell identity information; the network node implements synchronization policy according to its own synchronization status and the inquired synchronization status of the other network nodes. A system for synchronizing the network nodes in the time division duplex system is also disclosed, which includes an acquiring unit (60), an inquiring unit (61) and a implementing unit (62).