Abstract: Quantifying three-dimensional geomorphology feature of watershed synthetically and scientifically is one of key problems in the fields of geomorphology and watershed soil erosion prediction model. According to the obvious anisotropy and three-dimensional characteristics of watershed feature, based on multifractal theory, the GIS-based qualification model and its realization method of multifractal spectrums of watershed three-dimensional geomorphology was established firstly in the paper. Based on the established model and DEM data of study watersheds, multifractal spectrums and its main parameters of watershed three-dimensional geomorphology of seven typical sub-watersheds in Chabagou watershed were calculated and analyzed, and the multifractal features of watershed three-dimensional geomorphology of the seven study sub-watersheds and geomorphologic meanings of multifractal spectrums and its main parameters were studied finally. The results indicated that: 1) the qualification model established in the paper could be used to realize direct qualification of multifractal spectrums and its main parameters of watershed three-dimensional geomorphology; 2) the three-dimensional geomorphologies of the five sub-watersheds had significant multifractal features; 3) the multifractal spectrum and its main parameters could express the total three-dimensional geomorphologic characteristics of a watershed more sensitively and comprehensively than the simple fractal, and could scientifically represent and emphasize inner fine structure and abnormity partial variations of watershed three-dimensional geomorphology. The results in the paper provide a new approach and thought for synthetical and scientifical qualification of watershed three-dimensional geomorphology.