A data transmission method, characterized by: after determining multiple radio access technologies to be used, segmenting or concatenating, by a sending device, data packets of a first service to be transmitted, so as to generate a plurality of segments of data packets; for the multiple radio access technologies, packaging and numbering, by the sending device, the plurality of segments of data packets, wherein the multiple radio access technologies adopt an aggregation mode, and the aggregation mode indicates a mode in which different radio access technologies are used to transmit different contents; and sending, by the sending device, the packaged data packets to a receiving device by using corresponding radio access technologies according to the numbers, wherein the multiple radio access technologies comprise a first radio access technology and a second radio access technology, the plurality of segments of data packets comprise a first segment of data packets and a second segment of data packets, and the first segment of data packets and the second segment of data packets are respectively transmitted in the aggregation mode by using the first radio access technology and the second radio access technology, wherein before segmenting or concatenating, by the sending device, data packets of the first service to be transmitted, the method further comprises: acquiring, from an application, a Type of Service, ToS, list supported by the application, wherein the application supports multiple services, and the multiple services comprises the first service; and allocating the multiple radio access technologies to the application according to the ToS list, wherein the ToS list comprises ToSs of the multiple services, wherein the ToS comprises temporal distribution of data transmission. after determining multiple radio access technologies to be used, segmenting or concatenating, by a sending device, data packets of a first service to be transmitted, so as to generate a plurality of segments of data packets; for the multiple radio access technologies, packaging and numbering, by the sending device, the plurality of segments of data packets, wherein the multiple radio access technologies adopt an aggregation mode, and the aggregation mode indicates a mode in which different radio access technologies are used to transmit different contents; and sending, by the sending device, the packaged data packets to a receiving device by using corresponding radio access technologies according to the numbers, wherein the multiple radio access technologies comprise a first radio access technology and a second radio access technology, the plurality of segments of data packets comprise a first segment of data packets and a second segment of data packets, and the first segment of data packets and the second segment of data packets are respectively transmitted in the aggregation mode by using the first radio access technology and the second radio access technology, wherein before segmenting or concatenating, by the sending device, data packets of the first service to be transmitted, the method further comprises: acquiring, from an application, a Type of Service, ToS, list supported by the application, wherein the application supports multiple services, and the multiple services comprises the first service; and allocating the multiple radio access technologies to the application according to the ToS list, wherein the ToS list comprises ToSs of the multiple services, wherein the ToS comprises temporal distribution of data transmission. acquiring, from an application, a Type of Service, ToS, list supported by the application, wherein the application supports multiple services, and the multiple services comprises the first service; and allocating the multiple radio access technologies to the application according to the ToS list, wherein the ToS list comprises ToSs of the multiple services, wherein the ToS comprises temporal distribution of data transmission.