The invention discloses a subdistrict switching method which comprises the following steps of: adding a switching preparation timer into a source eNB (evolved Node B), starting the switching preparation timer after sending out a switching request message, judging whether a switching preparation subdistrict sending the message is the optimum switching preparation subdistrict when the source eNB receives a switching request ACK (ACKnowledge Character) message every time before the timer is overtime, if so, using the preparation subdistrict as a switching target subdistrict to issue a switching command to a UE (User Equipment) by the source eNB without waiting for receiving other switching request ACK messages any more, and if the optimum switching preparation subdistrict is still not selected until the timer is overtime, selecting the switching target subdistrict from the preparation subdistrict corresponding to all the received switching request ACK messages to issue the switching command to the UE. The invention also discloses an eNB. The UE can be accurately and rapidly switched to the subdistrict with good signal quality by adopting the subdistrict switching method and the eNB.