The apparent liquid permeability is of vital importance to studying the effective percolation capacity of shale reservoirs，and it is essential to explore the influence of negative slip length on apparent liquid permeability. Based on the fractal theory of porous media，the model of apparent liquid permeability was established，which comprehensively reflects the influence of pore structure，porosity，tortuosity，pore radius，and negative liquid slip length on apparent liquid permeability.According to the theoretical analysis，greater negative slip length leads to lower average percolation velocity of the liquid in micro/nanotubes；a larger pore radius results in less influence of negative slip length on percolation velocity. The ratio of apparent liquid permeability to Darcy permeability falls with the rise in negative slip length. The apparent liquid permeability goes up with the increase in fractal dimension of pores and down with the growth of tortuosity. The prediction results depending on the apparent liquid permeability model signals an 8.6% reduction in permeability caused by the slip effect.