The invention provides a data center system. The data center system comprises a plurality of first network address translation devices, a plurality of second network address translation devices and a plurality of servers. The plurality of first network address translation devices are used for receiving a first service request of a client side, carrying out source address and destination address translation on the first service request according to a rule to generate a second service request, and forwarding the second service request to one of the plurality of second network address translation devices; the plurality of second network address translation devices are used for receiving the second service request forwarded by the first network address translation devices, translating the source address and the destination address to generate a third service request, and forwarding the third service request to the servers through an extranet; the plurality of servers are used for receiving the third service request forwarded by the plurality of second network address translation devices, generating a corresponding third network response, and returning back the third network response to the second network address translation devices. The data center system is succinct in network structure, easy to develop and transparent to users in use, can be expanded smoothly, and also has the characteristics of being efficient, accurate, easy to use and expandable. The invention also discloses a data center service providing method.