Collapsing erosion is one of the sever land erosion types in southern red soil region as well as a major factor that threaten the regional ecological safety.Through improving remote image resolution to collect the collapsing，the comprehensive management and supervision to the collapsing erosion area will be enhanced.PCA，CN spectrum fusion，Brovey transform，Gram-Schmidt spectrum sharpening，NND iffuse Pan Sharpening，HPF highpass filter transform and the fusion algorithm of multiplicative are used to process the fusion of the Pleiades satellite imagery.Combining qualitative and quantitative method，the fusion results for different methods are analyzed comprehensively through average value，standard error，deviation index，entropy and spectral correlation data.The results demonstrate that CN spectrum fusion can ensure the whole spectrum fidelity.Object-oriented extraction of collapse area is closer to visual decoded area.Therefore，the CN spectrum fusion is a better method for the supervision and classification of the collapsing erosion area for the Pleiades satellite imagery.