To selectively remove HCN and crotonaldehyde from cigarette mainstream smoke, a series of tetrabutyl ammonium hydroxide-amino acid ionic liquids (TBAILs) were synthesized. The ionic liquids were characterized by FT-IR, NMR and TG. The results showed that TBAILs were successfully obtained and had good thermal stability below 150 °C. The adsorption of HCN and crotonaldehyde from cigarette smoke was evaluated by a homemade device and the preparation conditions were optimized. The optimum amino acids of TBAILs are threonine, serine, asparagine and phenylalanine while the reaction time is 6 h. The tetrabutylammonium hydroxide-threonine ionic liquid was applied in cigarettes in the form of paper-cellulose acetate dual filter. The yields of HCN and crotonaldehyde in mainstream smoke were reduced by 50.8% and 27.7% respectively at 10-mg loading, and 81.4% and 39.9% respectively at 20-mg loading, compared with the reference cigarettes. The removal performance was stable in 3 months. It can be seen that TBAILs have remarkable adsorption effect on harmful components in cigarette smoke, and good industrial applicability with simple preparation and lower cost.