The paper proposes a section-partition-based method for packet partitioning and restructuring, aiming at meeting the rigorous requirement of transmitting a great abundance of data reliably and real-timely in some specific situation in that the traditional UDP protocol has high efficiency but poor reliability. The time limit can be reset by adaptive congestion control algorithm of MIRD ( Multiplicative Increase Reduced Decrease ) by which the data can be transmitted reliably and also the fairness and stability of the bandwidth utilization can be improved. The method is validated to improve the reliability of the audio data transmission by the experiment.