The invention discloses a data transmission method and relates to the field of data transmission of communication technique. The method comprises a data transmission process of each path is divided into a plurality of non-overlapped periods to record time when data packets enter and leave a sending buffer memory in each period to calculate time when the data packets occupy the buffer memory; path quality is calculate in real time according to time when the data packets occupy the buffer memory and the size the data packets occupy the buffer memory; and paths with good quality are chosen periodically to be used as data transmission paths. According to estimation results and by means of data distribution scheduling algorithm, multipath data transmission is intelligently distributed and scheduled, sequential arrival of data packets is guaranteed as possible, and new retransmission mechanisms are introduced to distinguish and process data packet loss caused by different factors. The data transmission method can improve data transmission speed and quality, reduces data retransmission, reduces network load and furthermore improves experience effect of users of streaming media.