Abstract: Taking the development of Changsha Tobacco Intelligent Building management system as an example, an integrated system unifying centralized management, linkage control and information sharing was constructed based on OPC(OLE for Process Control)technique to solve the problems of information interacting and sharing between computer application programs and field equipment in a distributed control system. All sub-systems were accessed equally to reduce the complexity in multi-system integration. Standard data and interfaces were adopted for better system versatility, and the system could communicate with the management software at higher level as well. The test results showed that the time for transmission of real-time data and control commands was no more than 1 second, that of coordinated action commands was no more than 1.5 seconds and that for the response to fault image alarm was no more than 2 seconds. The OPC-based distributed control system realized the separation of hardware and software, and simplicated the integration of computers of different architectures, improved the flexibility of the integrated system and reduced the costs of upgrading and maintenance.