Embodiments of the present invention apply to the technical field of communications, and disclosed are a network switching method, system, and network side device. In the embodiment of the invention, within coverage of network side devices on one signaling plane, when a current network side device bearing data plane information of a terminal device determines that handover from the current network side device to a target network side device is required, the current network side device performs handover confirmation with the target network side device, so that the target network side device enables a data plane information communication function with the terminal device and completes switching the bearer of the data plane information.