Embodiments of the present invention relate to the communications field, and provide a method for determining a control plane node, an apparatus, and a wireless communications system, so as to select, for UE, a control plane node corresponding to a network slice to which the UE belongs, thereby ensuring that the control plane node can provide a customized service for the UE. The method includes: obtaining, by UE, indication information, where the indication information is used to indicate a network slice to which the UE belongs; and sending, by the UE, an access layer request message to a radio access network node, where the access layer request message includes the indication information, and the access layer request message is used to trigger the radio access network node to determine, based on the indication information, a control plane node corresponding to the network slice for the UE.