Aimed at the need of fully-automatical control of agricultural control system, the distributed intelligent greenhouse computerized control system has been researched. It is composed of center computer and single-chip microprocessor as its control core. Based on artificial intelligence and expert system knowledge database, the greenhouse environmental factors are adjusted in time with the help of real-time inspection and intelligent decision-making module. Furthermore, optimized growing conditions of crops will be created. The whole system is composed of environmental factors inspection module, intelligent decision-making module, data processing module, database management module, irrigation control module. The system owns many advantages such as intelligent decision-making, convenient operation. Besides, it is easy to extend and update. This system has been realized as a product.