can urbanization break through the “Hu Huanyong line”? This problem has aroused academic debate, different views, and has yet to be empirically tested. Whether urbanization can promote the coordinated development of both sides of the “Hu Huanyong line” is the essence of the problem. This paper makes an empirical study on the two kinds of provincial panel data of both sides of “Hu Huanyong line” from 2005 to 2021. The research shows that urbanization steadily promotes the growth of per capita GDP and the high growth of the northern region of the “Hu Huanyong line”, realizes the convergence of per capita GDP on both sides of the “Hu Huanyong line” and promotes the coordinated development of both regions. Further measurement results show that urbanization has increased the convergence rate of per capita GDP by 5.04%～47.33%, accounting for 44.32%～67.09% of the total convergence rate of per capita GDP. The marginal contribution of urbanization to per capita GDP growth is between 0.0278～1.2911. This means that China should vigorously promote the spatial layout of urbanization of “three vertical and two horizontal”, especially accelerate the urbanization of the northern region of the “Hu Huanyong line”, which will more effectively promote the development of the northern region of the “Hu Huanyong line”; At the same time, we should also increase fiscal revenue, the number of invention patents and the number of 10000 teachers to improve our ability of self-development; Take practical measures to encourage the transfer of population to urban agglomeration in the northern region of the “Hu Huanyong line”.