Embodiments of the present disclosure disclose a bearer setup method, a related apparatus, and a system. A first base station receives a first bearer setup request message initiated by UE; sends a first tunnel endpoint to a core network device, where the first tunnel endpoint includes a first TEID and a first transport layer address, and the first tunnel endpoint is allocated by the first base station; receives a second tunnel endpoint sent by the core network device, where the second tunnel endpoint includes a second TEID and a second transport layer address, and the second tunnel endpoint is allocated by the core network device; and completes setup of the first bearer with the core network device, for transmitting uplink data and transmitting downlink data.