A method for service transmission, comprising: determining, by a transmission device, that at least one first radio access technology in multiple radio access technologies is in an active state; and performing, by the transmission device, the service transmission by using the at least one first radio access technology; wherein the multiple radio access technologies support a service to be transmitted by the transmission device; the active state is a state in which the at least one first radio access technology has established a connection and performs a data transmission; the multiple radio access technologies further comprise at least one second radio access technology; characterized in that the at least one second radio access technology prefetches or caches sent data of a service, wherein prefetching or caching the sent data of the service comprises: prefetching or caching sent data of a preset data volume threshold value; or, prefetching or caching sent data of a preset time length; wherein the method further comprises: determining, by the transmission device, that the at least one second radio access technology is in a standby state, wherein the standby state refers to that the at least one second radio access technology has established a connection but there is no data transmission, or refers to that the at least one second radio access technology does not establish any connection but can establish a connection within a preset time length. determining, by a transmission device, that at least one first radio access technology in multiple radio access technologies is in an active state; and performing, by the transmission device, the service transmission by using the at least one first radio access technology; wherein the multiple radio access technologies support a service to be transmitted by the transmission device; the active state is a state in which the at least one first radio access technology has established a connection and performs a data transmission; the multiple radio access technologies further comprise at least one second radio access technology; characterized in that the at least one second radio access technology prefetches or caches sent data of a service, wherein prefetching or caching the sent data of the service comprises: prefetching or caching sent data of a preset data volume threshold value; or, prefetching or caching sent data of a preset time length; wherein the method further comprises: determining, by the transmission device, that the at least one second radio access technology is in a standby state, wherein the standby state refers to that the at least one second radio access technology has established a connection but there is no data transmission, or refers to that the at least one second radio access technology does not establish any connection but can establish a connection within a preset time length. prefetching or caching sent data of a preset data volume threshold value; or, prefetching or caching sent data of a preset time length; wherein the method further comprises: determining, by the transmission device, that the at least one second radio access technology is in a standby state, wherein the standby state refers to that the at least one second radio access technology has established a connection but there is no data transmission, or refers to that the at least one second radio access technology does not establish any connection but can establish a connection within a preset time length.