Embodiments of the present invention provide a method for switching a roadside navigation unit in a navigation system. The method includes: receiving, by an OBU, a switching notification message from a first RSU, where the switching notification message is used to instruct the OBU to prepare to switch a home RSU of the OBU from the first RSU to a second RSU; sending, by the OBU, a registration request to the second RSU to request to obtain local path information of the OBU within a coverage area of the second RSU; receiving, by the OBU, the local path information; and switching, by the OBU, the home RSU of the OBU from the first RSU to the second RSU according to the local path information.