Abstract: Since the opening-up of border areas, border ports and cities have become important engines and growth poles of economic
and social development. Taking 25 counties（cities）along the border of Yunnan Province as the research object, this paper analyzes
the net effect on economic growth and industrial structure adjustment brought by the opening-up to border counties（cities）by the
method of multiple difference. The results show that the opening of border ports has effectively promoted the economic growth of border
port counties（cities）, with a net effect of 19.031; the opening of border ports has also promoted the development of border port counties
（cities）, among which the growth effect on the tertiary industry is the most significant, the second industry the next, and the primary
industry the weakest; in terms of dynamic effect, with the strengthening of opening-up, economy of border port counties（cities）has
gained sustainable development, and the industrial structure has gradually evolved from "first-third-second" to "third-second-first"
model structure, but there is still no transition to "second-third-first". Under the initiative of B&R, ports will be a link for border areas
and cross-boarder areas. Border counties（cities）will build up an industrial chain as the link, forming a border economic belt and
trade cooperation belt with trade interaction, industry complementarity, resource sharing, mechanism linkage and coordinated
development.