With the development of Internet, various kinds of new applications appear constantly. They all have high requirements to the time delay, throughput, especially strong real-time applications such as mobile monitoring, video calls. The satellite network in Navigation Satellite System, which is necessary for the mobile monitoring, has many disadvantages such as asymmetric bandwidth, unstable network, high bit error rate and so on. This is a new challenge to the existing congestion control method. In order to improve the performance of congestion control mechanism, we put forward TCP-QS (Quick Start) from the TCP protocol control in this paper. TCP-QS algorithm mainly optimize the slow start stage. At the beginning of the connection, the value of parameter cwnd is set as a larger value according to the detected network bandwidth in which way, the time of the slow start stage is shortened during the transmission, and is adjusted the value of parameter ssthresh dynamically according to the change of network. When packet loss occurs, it takes different methods according to the different reasons.