This article first makes two hypotheses on the interaction mechanism between the development of the S&T business incubator and economic growth. Then the grey relational grade model is used to test and verify the interaction relation between the S&T business incubator's development and economic growth in China. And it concludes that the interaction mechanism between the development of the S&T business incubator and economic growth is an accumulated two-way interaction relation rather than a one-way advanced relation. In the end, some proposals are put forward to solve the problems on the interaction mechanism between the development of the S&T business incubator and economic growth in China.