By setting vegetation survey transect along the increasing direction of groundwater table depth (GTD) in Yuxi River basin,and based on the data of vegetation coverage,GTD and soil water content,the spatial scale represented by vegetation coverage and its influencing factors was obtained by Multivariate Empirical Mode Decomposition (MEMD),the driving factors of vegetation coverage spatial distribution were analyzed by structural equation,then the spatial pattern change characteristics of natural restoration and succession of vegetation communities were divided combining cluster analysis.The results showed that:(1) MEMD decomposed the multivariate spatial data into three intrinsic mode functions.After Hilbert's transformation,the corresponding spatial scales of each modal part were 14,27,and 38 km,respectively.(2) The maximum represent scale correlation analysis of structural equation model and MEMD after decomposition showed that the GTD had a significant negative correlation with vegetation coverage at the whole transect scale (R²=-0.95,p<0.001);taking GTD 5 m as the cut-off point,the correlation between soil moisture content and vegetation coverage was significantly positive in the GTD less than 5 m (Path coefficient is 0.68,p < 0.001),and significantly negative in greater than 5 m (Path coefficient is-0.43,p<0.01).(3) On this basis,combined with the results of systematic clustering classification,vegetation coverage was divided into the core area (GTD 0~3 m),transition area (GTD 3~4 m),stability area (GTD 4~5 m),peripheral area (GTD 5~10 m) sand marginal area (GTD 10~15 m).The results showed that the response of vegetation coverage to subsurface water had multi-scale characteristics in space,which can provide scientific basis for ecological restoration of sandy land and the protection and utilization of groundwater resources.