The work aims to study the effect of the contents of wetting agent W1, defoamer D1 and thickener T1 on flexible printing ink on film to improve the printability of flexible printing ink effectively. The optimum amount of wetting agent W1, defoamer D1 and thickener T1 was determined by testing the performance the viscosity, fineness, adhesion fastness and stability of the waterborne ink. Wettability of waterborne ink increased firstly and then decreased with the increase of wetting agent W1 content. The optimum amount of W1 was 0.6% to 0.9%. Viscosity of waterborne ink signif-icantly increased with the increase of thickener T1 content. When the content of T1 exceeded 0.9%, the viscosity of the waterborne ink sharply increased and the thermal stability was destroyed. When the mass fraction of defoamer D1 was 0.4%, it showed excellent defoaming ability and good adhesion and thermostability. The printability of water-based flexible printing ink used on films can be improved by adjusting the appropriate content of wetting agent, defoamer and thickener.