The invention belongs to the technical field of cigarette damage reduction and relates to a polyvinyl alcohol-amino acid porous hydrogel composite material for reducing harmful substances in a cigarette. Polyvinyl alcohol is swelled and dissolved by water, an amino material is added into the solution and the mixed solution is subjected to physical crosslinking so that the polyvinyl alcohol-amino acid porous hydrogel composite material is obtained. The polyvinyl alcohol porous hydrogel composite material has the characteristics of good biocompatibility, safety, reliability, unique hydroscopicity, water retention and moisture microenvironment adjustment. Through compounding of the polyvinyl alcohol porous hydrogel composite material and the amino material, the polyvinyl alcohol porous hydrogel composite material is prepared. The composite material and an acetate fiber filter stick or a cellulose paper filter stick are processed to form a binary or polybasic filter stick for a cigarette, the binary or polybasic filter stick can reduce crotonaldehyde content of main smoke of the cigarette by more than 28%, reduce a hydrocyanic acid release amount by more than 50%, and does not cause substantial appearance and quality change. Therefore, the polyvinyl alcohol-amino acid porous hydrogel composite material has a good popularization application value.