Abstract: DNS (Domain Name System), which provides domain name resolving service, is the basic service on the Internet. By the method of optimizing the DNS , which can be regarded as the promotion of the develop of Internet, we can shorten the time of query, reduce unnecessary quantity of net flow, enhance the safe ability of network. A basic constructor of DNS system qualified for the need on the level of telecomm in accordance with the industrial standard, which is composted by authorized DNS server, recursive DNS server and DNS manage system, support several methods of data backup, and every module can group freely in the way of modularly design. The system has the creative point that leads the internet market, hot database backup between master and slave and binding with customer IP, is described in the article. Both of the characters improve the existing DNS system in different ways, the former can be divided to general and private ways, in the general way AXFR and NOTIFY is used to transfer data in accordance with RFC, and in the private way the advanced database backup technology is introduced to the DNS and persist the data via the way of saving DML oriented with the character of database. The concept of virtual address pool is introduced in the former character to insert a new virtual level between the client and the IP of domain name so that the configuration of both sides can be set easily. As a result, load balance is achieved and a new solution for the safety of DNS is supplied. The hardware firewall can be substituted because in this way the same goal can be achieved. Finally a modeling environment is architected, large flux data is mocked by special software to test the ability of system, it is confirmed that the system is qualified for the need of telecomm.