Peer-to-peer network and application have boomed for the recent decade. However, Network Address Translation (NAT) devices obstruct its wide application by restricting the access to peers from private network. In this paper, we devise a peer strongly connected model to adapt Kademlia protocol to NAT-involved environment to minimize the impact on routine algorithm and meanwhile to make the target system reliable and scalable. Evaluation shows that our organization model highly outperforms existing model in delivery rate and scalability.