A communication method and a related device are disclosed. An evolved NodeB eNB receives a first message sent by a terminal device, where the first message is for requesting to access the eNB. The eNB sends a second message to the terminal device, where the second message includes a system message corresponding to at least one serving cell of a gNB, and the second message indicates the terminal device to be redirected to one of the at least one serving cell of the gNB, or the second message indicates the terminal device to be handed over to one of the at least one serving cell of the gNB. The terminal device receives the system message of the serving cell of the gNB from the eNB, to access the gNB.