In this paper, a scalable connection-based flow control scheme is proposed for application-specific network-on-chip (NoC). The proposed scheme exploits two distinctive characteristics of NoC, namely traffic predictability and abundant wire resource, to achieve significant performance enhancements. First, the burst injection data are regulated into constant data streams and a connection-based method is used to ensure that all links are not overloaded at any time. Consequently, the number of packets in the network is decreased, leading to a reduced congestion probability and improved communication performance. Second, a simple architecture of the central controller is proposed to guarantee that the proposed scheme has small area overhead and is scalable. Simulation results show that compared with traditional switch-to-switch (STS) flow control scheme and pre-allocation based flow control schemes, the proposed scheme greatly increases the throughput and cuts down the average latency with reasonable area and energy overhead.