Abstract: As a new cluster innovation mode which different from the independent innovation and cooperative innovation between enterprises, SCAI spiral model reveals an innovation mechanism, in which the spilled knowledge after external sublimation and then back to the spilled enterprise through active knowledge acquisition activity. This part of knowledge created outside have a high homology so it can absorb and integrate by spilled enterprise no barriers. By adopting the method of single case study, this article choose DALIAN Software Park as the research object, collect interview data, archives and documents to verify the validity of all data, and encode the data by grounded theory. This paper build the SCAI spiral model and analyze the effectiveness of dimension and measuring standard, find the rule of evolution of the cluster knowledge, and reveal that the SCAI spiral model is widely used by cluster enterprise in practice. This article develop the theory of cluster innovation and cluster knowledge theory, try to expand the knowledge creation theory from the enterprise level to the cluster level, develop the study on the relationship between the knowledge spillover and the cluster performance from the perspective of knowledge producers, and form the understanding of cluster innovation in different levels.