Method for improving strength of reconstituted tobacco substrate

The invention relates to a method for improving the strength of a reconstituted tobacco substrate. Polyvinyl alcohol is dispersed and dissolved in water to form a polyvinyl alcohol solution with the certain concentration, the polyvinyl alcohol solution is conveyed to a water spraying pipe after flow is adjusted by the frequency of a variable frequency water pump adjusted by a flow meter, the polyvinyl alcohol solution is uniformly sprayed to the back section of a water network or a wet paper page of a squeezing part through a fan nozzle on the water spraying pipe, and polyvinyl alcohol is diffused to the interior of the wet paper page and is further uniformly dispersed by squeezing and dewatering, so that the obtained reconstituted tobacco substrate is obviously improved in papermaking performance, the tensile strength is improved, the production efficiency is remarkably improved, and the labor intensity of personnel and the production and operation costs are obviously reduced. The polyvinyl alcohol contains