The work aims to investigate the effects of molecular structure of different film-forming additives on the properties of PUA ink film for wood inks. With film-forming additive as research object and PUA as linking agent, wood inks were prepared with defoamer and other additives. The effects of film-forming additives 3-methoxy- 3-methyl-1-butanol, ethylene glycol butyl ether, propylene glycol, diethylene glycol butyl ether and dipropylene glycol butyl ether on the properties of PUA wood inks were studied. FTIR was used to study the chemical structure of film-forming additive/binder composite emulsion film, and its hardness, adhesion and contact angle surface properties were characterized. The smaller the relative molecular weight of the additives, the greater the hardness and adhesion of the ink film. When the mass fraction of ethylene glycol butyl ether was 4%, the maximum hardness was 3H and the best adhesion was 0. The higher the relative content of ether bond and hydroxyl, the greater the hardness, adhesion and contact angle. When the mass fraction of propylene glycol was 4%, the contact angle was the maximal (95.3°). When the propylene glycol with mass fraction of 4% is selected as the film-forming additive, the comprehensive property is the best. The additives with small molecular weight and high polar group content should be given priority to in the selection of film-forming additives.