To provide elastic cloud services with QoS guarantee, it is essential for data centers to provision Virtual Machine(VM) instances rapidly. Due to bandwidth bottleneck of centralized model, the P2P-like distribution schemes are recently adopted. However, most of them just focus on the transmission speed, but ignore the impact on network bandwidth, especially for cloud data centers which are connected by Wide Area Network(WAN). In this paper, we propose a bridgehead-employed VM image distribution system(BIDS), which aims to minimize the repetitive data flows of WAN while speeding up the image distribution. In BIDS, we also design a version based image sharing mechanism, which tries to make a balance between efficiency and management complexity. Besides, we implement a Remote Management Console(RMC). The final evaluation shows that BIDS is of high efficient and low overhead.