This thesis focuses on multichannel halftone information hiding technology which can hide information into different shades of color master by phase modulation techniques. Depending on minimum threshold value matrix principle, the plus network screening technology based on phase modulation threshold value matrix was used in the base layer to position each channel of which the information was hidden in location. Besides, it's growth trend for the normal image part dot in mother board was changed to achieve modulation in location and thus to get good hiding conditions for each channel information. The results showed that the use of phase modulation technology could hide multichannel information and further achieve the desired effect of color information concealment. Therefore, it can expand the application of halftone screening information hiding technology in printing security and improve the security performance of information hiding techniques.