The invention discloses a determination method for the permeability of a paper-making reconstituted tobacco substrate coating liquid. The method includes the steps of: S01, cutting a smooth reconstituted tobacco substrate into round samples, performing folding and conducting opening from the middle to form cone, and putting the cone into a glass funnel; S02, using a pipette to suck 5-20ml of a coating liquid, transferring the coating liquid in the pipette all into the funnel, starting timing, letting the coating liquid gradually drip from the funnel into a conical flask, and taking out the conical flask 2-10min later; S03, mixing the solution in the conical flask uniformly, then detecting the turbidity, repeating the detection process and performing calculation to obtain the average turbidity T; S04, dripping a same volume of coating liquid directly into an equal amount of clear water, mixing the substances evenly, then performing detection to obtain turbidity T0, simultaneously detecting the clear water turbidity to obtain Tw; and S05, representing the permeability of the paper-making reconstituted tobacco substrate coating liquid as the permeability index X shown as the specification. The determination method for the permeability of a paper-making reconstituted tobacco substrate coating liquid provided by the invention has the advantages of simple operation and accurate measurement result.