The work aims to sort out the operation mechanism of AIGC in packaging graphic design and explore its application principles and methods, so as to provide a reference for the scientific application research of AIGC in packaging graphic design. Based on the analysis of AIGC technology and packaging graphic design related literature, AIGC tools were used to carry out the practice of packaging graphic design for Xiangxi Miao painting cultural and creative products, to summarize and verify the application process of AIGC in packaging graphic design. The operation mechanism of AIGC in packaging graphic design was constructed, and its application principles and methods were concluded. In conclusion, the use of AIGC for packaging graphic design can improve the design efficiency and optimize the design process, which affirms the positive role of AIGC in the design process. But for the overall control of the design process and the final decision of the design results, it is still inseparable from the designer's professional knowledge and practical experience.