Urban ecological space degradation in arid areas significantly affects citizen life, however, studies on this subject remained weak. Here, Shizuishan City (a representative city in arid regions in China) was used to explore the driving factors on urban ecological space degradation by employing plantation sample investigation, soil sampling, and Partial Least Squares Path Modeling (PLS-PM). The results showed that Margalef richness and Shannon diversity indices in more than 80 % of quadrats were below 1.0, indicating that plant species in Shizuishan City was scarce. Soil water content (SWC) in 68 % of quadrats was less than 8 %, soil organic carbon (SOC) in 32 % of quadrats was less than 1.5 %, and soil pH in 74 % of quadrats ranged from 8.54 to 9.94. Soil bacterial community exhibited higher similarity and more interspecific relationships relative to fungi and played a dominant role. Most of the dominant fungi were pathogenic and saprophytic fungi (such as Fusarium and Staphylotrichum). The soils in 64 % of quadrats was in moderate degradation. According to the data on PLS-PM, plant diversity was significantly affected by SWC, total phosphorus (TP), available potassium (AK) and bacterial richness, and soil pH had an indirect effect by driving AK. Plant richness was significantly related to soil available nitrogen (AN) and pH. Vegetation coverage was significantly influenced by SWC, dehydrogenase, invertase and fungal richness. Additionally, SWC and pH significantly affected vegetation coverage through fungal richness - invertase pathway, and bacterial richness significantly affected vegetation coverage through SOC - fungal richness pathway. Overall, SWC, pH, AN, TP, AK, dehydrogenase, invertase, and microbial richness significantly drove urban ecological space degradation, which thoroughly revealed the pathway of urban ecological space degradation. The results can provide a scientific basis for the restoration measures for degraded green spaces and the strategy for the sustainability of urban ecological spaces in arid cities.