For tight oil reservoirs，based on flow experiments and theoretical analysis，a new method for characterizing nonlinear percolation in tight oil reservoirs percolationwas developed. Based on the characteristics of dynamic resistance gradient in the percolation process of tight oil reservoirspercolation，this method adopted the flow experiment with reservoir cores to obtain three characterization parameters including starting pressure gradient，pseudo-starting pressure gradient，and measured liquid permeability. Thus，a new characterization model of nonlinear percolation in tight oil reservoirspercolation，i.e.，dynamic resistance gradient model，was built and verified on a single-well scale. The research results show that with the increase in displacement pressure，the dynamic resistance gradient gradually increases and is linearly correlated to the logarithm of the displacement pressure gradient. The mathematical characterization of nonlinear percolation is related to three parameters，namely starting pressure gradient，pseudo-starting pressure gradient，and measured liquid permeability.According to the three parameters，the characterization of nonlinear percolation in tight oil reservoirs was established based on flow experiments. From the perspective of reservoir application，the proposed characterization model is more accurate than the Darcy model and the pseudo-starting pressure gradient model.