Ecological vulnerability is one of the key issues that the international community cannot avoid in the face of a series of ecological problems. It is also one of the hot spots in the research of ecological civilization construction and green development. The paper, based on the SRP model, takes Zhangjiakou area as the research area, and selects 14 indexes to construct the index system of ecological vulnerability assessment in the study area, and combines the principal component analysis method with geodetector to carry out the research and analysis of the ecological vulnerability and its main driving factors in Zhangjiakou city. The results showed that in space, the ecological vulnerability of Zhangjiakou was characterized by a low to high pattern from the south to the north, which was consistent with the natural environmental characteristics of Bashang plateau (at a higher altitude) and the area below Bashang. The ecological vulnerability of Zhangjiakou decreased significantly from 2008 to 2016, and the proportion of light vulnerable area in 2008, 2012 and 2016 was 27.24%, 29.54% and 35.57%, respectively. In the last nine years, the proportions of severe and extremely ecologically vulnerable areas decreased from 30.96% to 1.29%, and the proportion of slightly and lightly ecologically vulnerable areas increased from 38.08% to 69.01%. The structure and function of ecosystem was developing in a positive direction. And the spatial distribution differences of ecological vulnerability in Zhangjiakou area were mainly related to the changes of slope, drought index, vegetation coverage and temperature. Due to high altitude, drought and less rain, the ecological fragility of Bashang plateau was generally high. The whole area below Bashang is slightly fragile, the ecological systems may have strong resistance to external interference, and the ability of self-recovery is strong. The results of 91 interactions indicate that the interaction between any two factors had greater influence on the ecological vulnerability of Zhangjiakou than the effect of any single factor, indicating that the ecological vulnerability of the region was affected by many factors. Based on the evaluation results of spatial principal component analysis and geodetector findings, suggestions for the development of ecological management in Zhangjiakou city are put forward.