The work aims to solve the problem that the infirm, unsmooth paste after heat sealing, wrinkled bubble, encapsulation and other defects of box transparent paper cannot be effectively detected and eliminated in the process of producing GDX1 packaging machine. A new visual detection system for heat-sealing defects of GDX1 box transparent flexible package paper was designed. Through the research on key technology, such as acquisition of dynamic image, design of MICRO II control program and mounting bracket, and adjustment of output control parameters, the defective heat-sealed cigarette packages of side transparent paper of the box could be efficiently detected and accurately eliminated. The result showed that, after implementing the system, the rejection rate of defective cigarette package was≥99.9%, and the wrong rejection rate was≤0.03%. The visual detection system can improve product quality, reduce material consumption, and provide guarantee for lean production and lean processing to some extent. The system and technology can be applied to all GDX1/2 packaging equipment in this industry.