On the basis of integrality model of industrial cluster surplus, this paper uses middleman transaction and repeated game models to analyze the cost-surplus realized path of two types of industrial cluster including the vertical and horizontal correlation types which are classified by the industrial links among enterprises, and gives cluster strategic choice to evade risk of transaction. It is suggested that as a regional economic system, enterprise cluster has new functions that its portion and subsystem do not have. In the transactions between enterprises of the horizontal correlation cluster and the supplier, clustering may act upon scale demand effect. With scale transaction by the middleman, the cluster can reduce cost, evade risk and improve efficiency and benefit to realize cost-saving effect. Through repeated games, the upper-tier and lower-tier enterprises of the vertical correlation type can avoid opportunistic behavior and realize the aim of decreasing transaction cost.