With the rapid development of urbanization, the ecological environment is being destroyed. Taking Barcelona Metropolitan Region as an example, this paper established an ecological environment quality assessment system suitable for different time and region based on remote sensing to evaluate it from 2006 to 2018. And built various OLS models to analyze multiple variables affecting the ecological environment. Finally, the characteristic triangular space structure was used to explain the interaction between the two key variables. The results showed that the ecological quality was unevenly distributed. The largest green space contributed the most ecological benefits, but its area was decreasing and its shape was more fragmented. NDVI was the most significant natural variable related to the distribution of green space. Precipitation was the most closely related climate factor to NDVI. And there was a complex two-way interaction mechanism between the two, and its boundary value was getting higher and higher. In conclusion: The environmental quality of BMR needs to be improved. There is a two-way relationship between the two key factors. The characteristic triangle can successfully explain the interaction mechanism between precipitation and NDVI.