Maintaining the coordinated correlation between the ecological environment and economic development is one of the important strategies in the initial stages of national poverty alleviation and development. Taking Gansu Province as a study area, we designed a dual system development multi-index comprehensive evaluation system based on the theory of system coupling coordination degree. Between 2000 and 2014, we measured and analyzed the scores of vulnerable ecological environment and poverty and the coupling degree and spatio-temporal variability in the study area. The vulnerable ecological environment and poor coupling degree of Gansu showed a general rising trend, but exhibited three stages that were affected by factors such as policy adjustment. From the point of view of spatio-temporal variability, the coupling degree of vulnerable ecological environment and poverty increased from the southeast to the northwest, whereas spatial distribution was unbalanced. Given that the vulnerable ecological environment coexists with poverty, the strategic significance of protecting the environment of poor areas should be given full consideration.