The work aims to solve the problem that the inkjet system installed above the belt conveyor in the cigarette sorting operation was easily affected by the irregularity and color of cigarette and the ambient light, thus resulting in such problems as a large number of missing sprayed codes. TRIZ theory was applied in the innovation design of inkjet system. According to the reaction principle and the physical/chemical state change principle, the inkjet system was installed at the bottom of the belt conveyor floor, and the color code with higher color recognition sensitivity was used to detect the photoelectric sensor. The number of average missing sprayed codes of cigarettes of the improved inkjet system in each month was reduced from 305 to 4.3, which improved the sorting efficiency of cigarette distribution. It shows that the direction of problem solving determined by the TRIZ theory is feasible, which can effectively solve the engineering problems in optimal design of cigarette inkjet system.