A data transmission method, applied to user equipment UE, wherein the method comprises: in a dual-connectivity mobility management procedure, in a case that first information is used to indicate that a first path is capable of transmitting uplink data, transmitting first uplink data on the first path, and/or in a case that the first information is used to indicate that a second path is incapable of transmitting target uplink data, and that the first uplink data are the target uplink data, skipping transmitting the first uplink data on the second path; and characterized in that a data type of the target uplink data comprises any one of the following: PDCP layer data packet, PDCP layer control packet, and PDCP layer data, wherein in a case that a PDCP entity of the UE buffers second data and third data, that the second data is data transmitted through the first path, and that the third data is data transmitted through a second path, the method further comprises: transmitting second information to a MAC entity corresponding to the first path and transmitting third information to a MAC entity corresponding to the second path; wherein the second information is used to indicate a data amount of the second data, and the third information is used to indicate a data amount of the third data, the first path is a target path of a handover procedure or an SCG change procedure, and the second path is a source path source path of a handover procedure or an SCG change procedure. in a dual-connectivity mobility management procedure, in a case that first information is used to indicate that a first path is capable of transmitting uplink data, transmitting first uplink data on the first path, and/or in a case that the first information is used to indicate that a second path is incapable of transmitting target uplink data, and that the first uplink data are the target uplink data, skipping transmitting the first uplink data on the second path; and characterized in that a data type of the target uplink data comprises any one of the following: PDCP layer data packet, PDCP layer control packet, and PDCP layer data, wherein in a case that a PDCP entity of the UE buffers second data and third data, that the second data is data transmitted through the first path, and that the third data is data transmitted through a second path, the method further comprises: transmitting second information to a MAC entity corresponding to the first path and transmitting third information to a MAC entity corresponding to the second path; wherein the second information is used to indicate a data amount of the second data, and the third information is used to indicate a data amount of the third data, the first path is a target path of a handover procedure or an SCG change procedure, and the second path is a source path source path of a handover procedure or an SCG change procedure. transmitting second information to a MAC entity corresponding to the first path and transmitting third information to a MAC entity corresponding to the second path; wherein the second information is used to indicate a data amount of the second data, and the third information is used to indicate a data amount of the third data, the first path is a target path of a handover procedure or an SCG change procedure, and the second path is a source path source path of a handover procedure or an SCG change procedure. <EOS>