After a comprehensive analysis for the influential factors like anti-erodibility chemical constitutes, mineral components and micro-structure characteristics of the Pisha-sandstone, and by combining AHP and grey correlation analysis, the anti-erodibility quantitative comparison for 5 types of Pisha-sandstones in Ordos is made on the basis of the grey multi-layer comprehensive assessment mode. The result shows that, from the anti-erodibility point of view, the order of those types is: Pink sandstone, celadon sandstone, purple sandstone, grey sandstone and commixed sandstone. For the evaluation process adopts a simple method, a direct, reasonable and practical result is given, which is also identical to the result of the field survey on soil and rock erosion problems. Consequently, the research on the Pisha-sandstone’s anti-erodibility issue is turned from the qualitative description process to the quantitative evaluation stage.