Consistency, availability, scalability, and tolerance to the network partition are four important problems in distributed systems. In this paper, we have designed a consistent, highly available distributed key value storage system that can run on lots of general devices and solve the four problems in distributed systems, we call it as PaxStore. It uses zookeeper to complete leader election. It uses a centralized Paxos-based protocol to guarantee the strong replica consistency. The system node can automatically recover in case of failure. Experiments show that PaxStore can guarantee the strong consistency and only increases 20% overhead compared with local systems. By using log optimization, such as the circular lock-free queue and Paxos protocol optimization techniques, PaxStore has a high performance and recovery speed than the older system which uses a basic Paxos protocol.