Commonly, strange folding cartons need the design of un-forming scoring line due to their special and complicated structures. According to the types of strange cartons, the un-forming scoring line design of the types of slash, curve and arch was studied. Some cases of such designs were given. The calculation and design methods of un-forming scoring line of strange folding carton for easy placement and transportation stack were obtained. Some influencing factors needed to be focused in packaging protection, graphic information communication, and processing cost were put forward for design of un-forming scoring line of strange folding carton.