TCP communication protocol-based congestion window control algorithm and system

The present invention discloses a TCP communication protocol-based congestion window control algorithm and system, wherein the method comprises the steps of monitoring the actual throughput and the continuous packet loss number of a network; according to the actual throughput of the network and a desired throughput, obtaining the network time delay change; determining whether the network time delay change is greater than a first threshold value and whether the continuous packet loss number is greater than a second threshold value; if yes, determining that the network congests, and updating a slow start threshold value according to a measured network available bandwidth; and setting the size of a congestion window according to the slow start threshold value. The method can determine whether the network congests accurately according to the network time delay change and the packet loss property, and can set the congestion window according to a real-timely monitored bandwidth estimation value when the network is determined to congest, so that the congestion window can converge to an actual bandwidth faster, the utilization rate of the bandwidth resources is improved, and the user experience is improved based on the operation speed of a TCP application.