To explore the relationship between pore fractal dimension characteristics and permeability in Malan loess. Based on mercury injection test, pore fractal dimensions of different scales were calculated based on various fractal models, and the correlation between the results and measured permeability coefficient and theoretical permeability coefficient was analyzed, and the optimal model was selected to provide important reference value for permeability. (1) The mass fractal dimension was positively correlated with the permeability coefficient in the scale range of 430~2 μm、32~ 0.2 μm、430~ 0.2 μm, and the correlation was more than 0.79; the volume fractal dimension had a negative correlation with the permeability coefficient only in the range of 430~ 0.2μm, and the correlation was more than 0.70; (2) At the same time, the displacement pressure and micropore content have negative correlation with the mass fractal dimension and positive correlation with the median pore size, which is opposite to the volume fractal dimension. Finally, both the mass fractal dimension of porosity and the volume fractal dimension of pore size collocation are important reference for evaluating the of permeability Malan loess.