The invention discloses a method for measuring the coating ratio of a paper-making reconstituted tobacco product. The method comprises the following steps: S1, placing filter paper with the oven dry weight being m into a Buchner funnel connected with a suction flask; S2, adding a product with the percent content of the oven dry matter being d and with the weight being a into a fiber fluffer containing a certain amount of water, and carrying out defibering, thus obtaining a suspension; S3, pouring the suspension into the Buchner funnel in S1 for suction filtration, and carrying out detection by adopting an oven-drying method, thus obtaining filter paper having the oven dry weight being m' and containing a sizing agent; S4, calculating the coating ratio according to the formula in the description; and S5, or repeating S1-S4, and calculating the average coating ratio according to the following formula: delta C= (C1+C2+...+CN)/N. The method provided by the invention is easy and rapid to operate, the measuring result is accurate, the measuring efficiency in the production, application and technology researches of paper-making reconstituted tobacco is improved, and the economy and practicability are very good.