Abstract:he fiercely competitive environment drives enterprises to implement open innovation strategies to break through organizational boundaries and make up for their inadequacy to promote enterprise growth by acquiring rich external knowledge. However, the theoretical analysis and empirical research on the relationship between innovation openness, enterprise growth and knowledge acquisition are inadequate in academic circles. For this reason, the structural equation model is used to study and verify the relationship among 316 high-tech enterprises in China. The results show that the effects of the breadth and depth of innovation openness on the growth of high-tech enterprises are different, and the mediating role of different types of knowledge acquisition is also different. The breadth of innovation openness has no significant effect on enterprise growth, while the depth of innovation openness has a positive effect on enterprise growth. The breadth of innovation openness has no significant effect on explicit knowledge acquisition and a positive effect on tacit knowledge acquisition, while the depth of innovation openness has a positive effect on both explicit knowledge acquisition and tacit knowledge acquisition. The effect of explicit knowledge acquisition on enterprise growth is not significant, while tacit knowledge acquisition plays a fully mediating role between the breadth of innovation openness and enterprise growth, and a partially mediating role in the positive effect of innovation openness depth on enterprise growth. Thus, we get the following insights: enterprises should attach importance to open innovation strategy and make reasonable and efficient use of open innovation networks. Enterprises should continuously improve the depth of innovation openness and effectively control the breadth of innovation openness. Enterprises should pay attention to acquiring knowledge in various ways, especially tacit knowledge.