Embodiments of the present application relate to the technical field of wireless communication, in particular a D2D switchover method, system, and device, for solving the problem in prior art of the lack of mechanism for D2D switchover for D2D user devices under appropriate conditions so as to ensure the short-distance transmission quality in the situation where an LTE system has too high a load and interference is too strong. Embodiments of the present invention comprise: a network device determines, according to resource management information and/or channel status information whether a D2D user device needs to perform a D2D switchover; when the D2D user device is determined to need to perform a D2D switchover, the D2D user device is triggered to switch to a heterogeneous system and conduct end-to-end communication, or to conduct end-to-end communication via the network device, or to conduct in the current system end-to-end communication not controlled by the network device. The method in the embodiments of the present invention ensures that D2D devices can perform D2D switchover under appropriate conditions even when an LED system has too high a load and interference is too strong, thereby enhancing the end-to-end communication performance.