Provided is a design of a virtual firewall assembly acting on a cloud computing data center security domain. The invention relates to Web direction network security production, and particular relates to a network security technology under a cloud computing environment. The technical scheme is that the firewall assembly is operated via a distributed deployment security gateway so that customized and distributed security protection of the overall data center is completed. A new firewall system structure comprises the following parts: the unified security gateway, the network firewall assembly and central management. The firewall assembly based on a data packet filtering technology is realized. The assembly operates in the unified security gateway. Network traffic is controlled by using the data packet filtering technology, distributed deployment is used and customized security protection of the overall data center is completed.