The enterprise clusters are many enterprises in the same region, which are centralized to produce the same mass products. In the context of globalization, the enterprise clusters are becoming an important force of the leading world economy. Based on investigating and analyzing for the enterprise clusters in south China, the local area networks of the enterprise clusters can be built by using multi-level distributed computer system. The CAD and MIS systems are integrated into the local area networks of the enterprise clusters so that the flexible manufacturing systems can gain manufacturing data from the integrated systems. So, the integrated systems greatly improve the productivity of the enterprise clusters. The CAD and MIS system integration model of intelligentization has been dwelt on in this paper.