It aims to study the residual behavior of UV ink photoinitiators in food packaging materials. With the two commonly used photoinitiators EDB and 907 as objects of study and PET film and art paper as substrates, thickness of printing film was controlled by IGT printability tester and polymerization time of ultraviolet light was controlled by IGT UV dryer. The effect of light energy, ink thickness and ink density on residual photoinitiators in food packaging materials was investigated. The results showed that the amount of residual photoinitiators decreased as light energy increased but grew as ink thickness became bigger. For PET film, residues in high-density ink were higher than those in low-density ink. Conversely, for art paper, residues were less in high-density ink. In conclusion, light energy should be increased in practical UV ink printing. Inks of different densities should be applied to different substrates so as to reduce residual photoinitiators, lower the risk of transition, and improve the safety of food packaging.