Abstract: An innovation diffusion model in cluster network is established from the perspective of social network theory, and the influence of the cluster innovation network structure on the diffusion of innovation behavior by using simulation technology. Research shows that the cluster network structure makes the diffusion efficiency of innovation information more higher, and the innovation diffusion process faster. At the same time, the social impact of cluster network has an important effect on the cluster innovation diffusion speed. When the sensitivity cluster subject to society is low, social effect will contribute to the diffusion of innovation information in the cluster network, and when the sensitivity cluster subject to society is relatively large, social effect will hinder the diffusion of innovative information in the cluster network.