Abstract: In order to obtain the coupling relationship between the accessibility and the degree of spatial poverty in the counties, this paper first uses the weighted time cost distance model of the road network and grid integration method to calculate the traffic accessibility of the county, and constructs the spatial poverty evaluation index system based on “3D” theories, respectively. Then, the spatial coupling mechanism of the traffic accessibility and spatial poverty is obtained based on the structural equation model, taking Western Yunnan border area as an example. The results show that first there are significant spatial differentiation and proximity effect of the poor counties (regions) in the western Yunnan border area. Improving the backbone road network has a positive relationship with the outside accessibility of counties. Second, the incidence of poverty in the western Yunnan border area shows the spatial characteristics of divergence and agglomeration distribution. The poverty alleviation is positively related to GDP per land, market distance, industrial distance, traffic segmentation and poverty segmentation. However, it has a negative effect on population density. Third, the coupling intensity of spatial poverty and traffic accessibility in this region is 023, showing significant negative interactions. Improving the whole accessibility level especially that between counties could provide strongly support for poverty alleviation and the development of social economics