Method, device and system for switching of heterogeneous networks

The invention discloses a method, device and system for switching of heterogeneous networks and relates to the communication technology. When network side devices of a base station and the like determine that UE needs to be switched to a non-3GPP network, a switching signaling carrying switching instruction information is sent to the UE, the switching instruction information is used for instructing the UE to switch part of or all loads to the non-3GPP network from a 3GPP network, and therefore the UE can switch part of or all the loads to the non-3GPP network from the 3GPP network according to the switching instruction information. According to the method, device and system, switching of the heterogeneous networks at the network side is achieved.