The present disclosure discloses a communication method, a network device, user equipment, and a communications system. The communication method includes determining, by a network device, to allocate a first secondary cell group (SCG) to user equipment, and sending, by the network device, first configuration indication information to the user equipment, where the first configuration indication information indicates at least one type of the following configuration transmitting uplink control information related to a cell in the first SCG by using a physical uplink control channel (PUCCH) of a first cell, where the first cell belongs to a second SCG of the user equipment, or processing data transmission on at least one cell in the first SCG by using a layer 2 functional entity located in the second SCG. The communication method disclosed in the present disclosure can reduce complexity of UE.