Independent innovation and knowledge spillover are two main ways to improve knowledge storage and catch up with technology for backward enterprises. Knowledge spillover, as one of the prominent characteristics of industrial clusters, has an important impact on the innovation and development of industrial clusters. Based on the knowledge spillover model of Verspagen and Caniëls, this paper constructs an industrial cluster knowledge spillover model according to the characteristics of high and new technology industry cluster. Then this model is used as an analytical tool to analyze the technology catching up with gap of knowledge storage for technological backward enterprises under the joint effect of knowledge spillover and independent innovation. And then the influence factors of knowledge spillovers how to impact technology catching up of backward enterprises. And then, we do empirical study based on the data of Zhongguancun Science and Technology Park. In the end, some suggestions are put forward for technological backward enterprises to catch up in hi-tech industrial development zones.