A data transmission method, comprising: receiving, by a base station, N streams of video data uploaded by a video capture terminal (step 101); uploading, by the base station, the N streams of video data to a dispatch station being a head station and configured to determine, according to the received N streams of video data, the video data to be looped back; receiving, by the base station, loopback indication information sent by a mobility management entity or the video capture terminal, wherein the loopback indication information carries an identifier of a bearer of video data to be looped back (step 102); confirming, by the base station, according to the identifier of the bearer of the video data to be looped back, the video data to be looped back corresponding to the identifier of the bearer of the video data to be looped back (step 103); and sending, by the base station, the video data to be looped back to a trunking terminal (step 104), wherein the identifier of the bearer is an identifier of the bearer among N bearers that are set up by the mobility management entity according to a bearer setup request of the video capture terminal and are used for transmitting the N streams of video data, wherein the bearer setup request carries a serial number for each of the N streams of video data, the serial number of each stream of video data corresponds to the identifier of the bearer used for transmitting each stream of video data, and the identifier of the bearer of the video data to be looped back is determined by the mobility management entity or the video capture terminal according to a serial number of the video data to be looped back carried in a video loopback request received by the mobility management entity or the video capture terminal from the dispatch station, wherein N is an integer greater than or equal to 1. receiving, by a base station, N streams of video data uploaded by a video capture terminal (step 101); uploading, by the base station, the N streams of video data to a dispatch station being a head station and configured to determine, according to the received N streams of video data, the video data to be looped back; receiving, by the base station, loopback indication information sent by a mobility management entity or the video capture terminal, wherein the loopback indication information carries an identifier of a bearer of video data to be looped back (step 102); confirming, by the base station, according to the identifier of the bearer of the video data to be looped back, the video data to be looped back corresponding to the identifier of the bearer of the video data to be looped back (step 103); and sending, by the base station, the video data to be looped back to a trunking terminal (step 104), wherein the identifier of the bearer is an identifier of the bearer among N bearers that are set up by the mobility management entity according to a bearer setup request of the video capture terminal and are used for transmitting the N streams of video data, wherein the bearer setup request carries a serial number for each of the N streams of video data, the serial number of each stream of video data corresponds to the identifier of the bearer used for transmitting each stream of video data, and the identifier of the bearer of the video data to be looped back is determined by the mobility management entity or the video capture terminal according to a serial number of the video data to be looped back carried in a video loopback request received by the mobility management entity or the video capture terminal from the dispatch station, wherein N is an integer greater than or equal to 1.