In this study, the surface soils (0-20 cm) with different erosion degrees were selected in Baojiagou watershed of Feldspathic sandstone region through canonical correlation and multifractality, and then the relationship between soil PSD and soil WHC was studied. The results showed that: 1) Soil particle size was distributed in range of 2.13-2 390 μm, sands dominated soil particle composition, while silts and clays were little. Soil sands increased gradually with erosion intensified. 2) The general dimension spectrum D(q) showed Z-shape decreasing function, and D₀>D₁>D₂, which indicated a high degree of homogeneity, therefore multifractality could be used to describe the characteristics of PSD. 3) Soil porosity ranged from 33.07% to 46.20%. Soil porosity and WHC decreased gradually with erosion intensified. In conclusion, soil particle multi-fractals is positively correlated with soil WHC, and soil aeration porosity and correlation dimension of PSD play a guiding role in the interaction process.