A data transmission method in a Radio Resource Control, RRC, Inactive state, wherein the method is performed by a first node device, and the method comprises: when a Retrieve UE Context Request message is received (S1030, S1160, S1260, S1330, S1340) from a second node device, in response to the Retrieve UE Context Request message, sending (S1050, S1180, S1290, S1350, S1490) an interface message including at least one Packet Data Convergence Protocol, PDCP, Protocol Data Unit, PDU, to the second node device; wherein the second node device is a current serving node of a user terminal in the RRC Inactive state, and the first node device is an anchor node of the user terminal; wherein the at least one PDCP PDU is to be sent from the second node device to the user terminal, wherein the at least one PDCP PDU includes an RRC message; wherein said method is characterized in that, the RRC message comprises at least one of: indication information instructing the user terminal to send an uplink RRC message to the second node device through a default first signaling radio bearer SRB 1: indication information instructing the user terminal to continue to receive a downlink RRC message from the second node device through the default SRB1; indication information instructing the user terminal to send the uplink RRC message to the second node device through a default second signaling radio bearer SRB2; or indication information instructing the user terminal to receive the downlink RRC message from the second node device through the default SRB2. when a Retrieve UE Context Request message is received (S1030, S1160, S1260, S1330, S1340) from a second node device, in response to the Retrieve UE Context Request message, sending (S1050, S1180, S1290, S1350, S1490) an interface message including at least one Packet Data Convergence Protocol, PDCP, Protocol Data Unit, PDU, to the second node device; wherein the second node device is a current serving node of a user terminal in the RRC Inactive state, and the first node device is an anchor node of the user terminal; wherein the at least one PDCP PDU is to be sent from the second node device to the user terminal, wherein the at least one PDCP PDU includes an RRC message; wherein said method is characterized in that, the RRC message comprises at least one of: indication information instructing the user terminal to send an uplink RRC message to the second node device through a default first signaling radio bearer SRB 1: indication information instructing the user terminal to continue to receive a downlink RRC message from the second node device through the default SRB1; indication information instructing the user terminal to send the uplink RRC message to the second node device through a default second signaling radio bearer SRB2; or indication information instructing the user terminal to receive the downlink RRC message from the second node device through the default SRB2. indication information instructing the user terminal to send an uplink RRC message to the second node device through a default first signaling radio bearer SRB 1: indication information instructing the user terminal to continue to receive a downlink RRC message from the second node device through the default SRB1; indication information instructing the user terminal to send the uplink RRC message to the second node device through a default second signaling radio bearer SRB2; or indication information instructing the user terminal to receive the downlink RRC message from the second node device through the default SRB2.