An interface establishing and communication method, wherein the method comprises: • sending, by a serving node, instruction information to an anchor node, wherein the instruction information is used to instruct to establish a first interface between the serving node and the anchor node, wherein the first interface comprises a control plane interface, and the control plane interface is used to transmit a radio resource control message of a user terminal (S 302); • receiving, by the serving node, response information from the anchor node in response to the instruction information (S 303); wherein in a first alternative, the method further comprises the following steps: ∘ receiving, by the serving node, an uplink Radio Resource Control, RRC, message carried in a signaling radio bearer, SRB, o from the user terminal; ∘ processing, by the serving node, the uplink radio resource control message carried in the SRB0 (S 304); ∘ receiving, by the serving node, an uplink RRC message carried in a SRB1 from the user terminal; ∘ sending, by the serving node through the first interface, the uplink RRC message carried in the SRB 1 to the anchor node for processing (S 305); or, in a second alternative instead of the first alternative, the method further comprises the following steps: ∘ generating, by the serving node, a downlink RRC message carried in the SRB0; ∘ sending, by the serving node, the generated downlink RRC message in the SRB0 to the user terminal (S 306); ∘ receiving, by the serving node, a downlink RRC message carried in the SRB1 through the first interface from the anchor node; ∘ sending, by the serving node, the downlink RRC message carried in the SRB1 to the user terminal (S 307). • sending, by a serving node, instruction information to an anchor node, wherein the instruction information is used to instruct to establish a first interface between the serving node and the anchor node, wherein the first interface comprises a control plane interface, and the control plane interface is used to transmit a radio resource control message of a user terminal (S 302); • receiving, by the serving node, response information from the anchor node in response to the instruction information (S 303); wherein in a first alternative, the method further comprises the following steps: ∘ receiving, by the serving node, an uplink Radio Resource Control, RRC, message carried in a signaling radio bearer, SRB, o from the user terminal; ∘ processing, by the serving node, the uplink radio resource control message carried in the SRB0 (S 304); ∘ receiving, by the serving node, an uplink RRC message carried in a SRB1 from the user terminal; ∘ sending, by the serving node through the first interface, the uplink RRC message carried in the SRB 1 to the anchor node for processing (S 305); ∘ receiving, by the serving node, an uplink Radio Resource Control, RRC, message carried in a signaling radio bearer, SRB, o from the user terminal; ∘ processing, by the serving node, the uplink radio resource control message carried in the SRB0 (S 304); ∘ receiving, by the serving node, an uplink RRC message carried in a SRB1 from the user terminal; ∘ sending, by the serving node through the first interface, the uplink RRC message carried in the SRB 1 to the anchor node for processing (S 305); or, in a second alternative instead of the first alternative, the method further comprises the following steps: ∘ generating, by the serving node, a downlink RRC message carried in the SRB0; ∘ sending, by the serving node, the generated downlink RRC message in the SRB0 to the user terminal (S 306); ∘ receiving, by the serving node, a downlink RRC message carried in the SRB1 through the first interface from the anchor node; ∘ sending, by the serving node, the downlink RRC message carried in the SRB1 to the user terminal (S 307). ∘ generating, by the serving node, a downlink RRC message carried in the SRB0; ∘ sending, by the serving node, the generated downlink RRC message in the SRB0 to the user terminal (S 306); ∘ receiving, by the serving node, a downlink RRC message carried in the SRB1 through the first interface from the anchor node; ∘ sending, by the serving node, the downlink RRC message carried in the SRB1 to the user terminal (S 307).