While promoting the economic development in poor areas, the construction of traffic network has also brought many influences on the ecological environment in many aspects. It is of great significance to deal with the relationship between economic development and ecological environment for realizing the coordinated development of economy and ecology. The study based on the poor county district Fengjie and the non-poor county Fuling of Chongqing in three time nodes in 2010, 2014 and 2018. We are trying to use the road network data and ecological footprint data of these three years to build two index systems of road network accessibility and ecological environment pressure. The road network accessibility degree to choose the way of two indicators of road density and road connectivity to representation, ecological environment pressure was chosen by using the ecological footprint of characterization to explore. The factors "construction land" and "fossil energy land" that have greatest impact on the expansion of the road network in the ecological footprint will be added up to form "construction-chemical footprint". And then by calculating growth rate index comparison road density, road connectivity, and "construction-chemical footprint" after the change trend between the three to explore the changes of the internal ecological footprint and the relationship between the road accessibility degrees. The results showed us as the followings below: (1) The four indicators of road connectivity, road density, ecological deficit and "construction-chemical footprint" increased year by year in the poor and non-poor areas in southwest mountainous areas, and the overall trend of change was almost same. And especially the poor area and county showed a faster growth trend than another during the researching period. (2) The ecological environment pressure of the poor and non-poor areas in the southwest mountainous area was further expanded during the researching period, which that seems to indicate that the overall relationship between economic construction and ecological development is in a state of disharmony and may continue to deteriorate. (3) During the researching period, the increase rates of the "construction-chemical footprint" and road connectivity in the poor mountainous areas of Southwest China were 0.40 and 0.42 respectively. Therefore, the relationship between them is consistent. It's indicating that the road layout structure has greater pressure on the ecosystem. In the study period, the increase rates of "construction-chemical footprint" and road density in non-poor areas are 0.34 and 0.33 respectively, so the relationship between them is relatively consistent, indicating that the ecological environment pressure is more affected by the scale of road construction. The conclusions of this research have reference value for the development of transportation infrastructure, ecological environment planning and regional development strategy in poor mountainous counties.