Network switching method and device and mobile terminal

The embodiment of the invention discloses a network switching method, which comprises the following steps: when a mobile terminal is in a mode that a first network is closed and a second network is connected, acquiring a radio resource control connection reconfiguration message sent by a base station; if the radio resource control connection reconfiguration message contains a cell measurement request of the first network, performing cell measurement on the first cell based on the cell measurement request to obtain a measurement result, the measurement result comprising a target first cell satisfying a preset reporting condition; the measurement result is sent to the base station, so that the base station generates a radio resource control release message according to the measurement result, and the radio resource control release message comprises a to-be-connected first cell in the target first cell; and acquiring a radio resource control release message sent by the base station, disconnecting the connection