The invention relates to a method for improving permeability of coating liquid of reconstructed tobacco leaves. The method includes the steps of putting a substrate into a side coating roll to enablethe Shore hardness to be reduced from commonly used more than eighty to around fifty and enable deformation of a roll surface to be larger and a pressure zone to be wider, so that the coating liquid on the surface of the substrate can have a long time to permeate from the surface of the substrate to the inside of the substrate, and the permeability of the coating liquid can be improved preliminarily under the condition of meeting the coating rate. Penetrants are sprayed to the upper surface of the coated substrate in an atomized mode, the larger amount of coating liquid attached to the upper surface of a paper sheet after being diluted by water mist permeates to the inside of the paper sheet, so that the adhesion amount of the coating liquid on the upper surface of the paper sheet is reduced, color difference on both sides is reduced, the phenomenon of white core and caking of products is avoided, and appearance physical quality and inner sensory quality of the products are stabilized.