Based on the inter-provincial high-tech industry panel data from 2010 to 2016 in China, this study constructs static and dynamic panel models, respectively, to study the relationship between high-tech industry agglomeration and high-tech export product upgrading, and makes an in-depth discussion on open innovation to achieve sustainable development through industry agglomeration. This paper studies and tests the transmission mechanism between high-tech industrial agglomeration and export product upgrading, which makes up for the research gap in industry agglomeration. The results show that: (1) China’s high-tech industry agglomeration has a significant positive effect on its export industry product upgrading. (2) Regional education has a significant positive effect on the high-tech industry’s export product upgrading, and the influence of high-tech industry agglomeration on export product upgrading is negatively regulated by regional education. (3) From the perspective of influence mechanism, high-tech industry agglomeration has a positive effect on high-tech export product upgrading mediated by innovation and openness (open innovation), and then affects the sustainable development of a regional economy. (4) The high-tech industry agglomeration has a heterogeneous effect in promoting their export products; in terms of scale, the promotion effect is more significant in the large enterprises than small- and medium-sized enterprises; in terms of region, the eastern and western regions have a more significant role in promoting export product upgrading; in terms of industries, the electronic and communication equipment manufacturing industry has the most obvious promotion effect. Based on the research results, this study puts forward policy suggestions such as increasing investment in high-tech industries, strengthening the degree of opening to the outside world, encouraging enterprise innovation, and promoting balanced development of the industry.