Bottlenecks are the core elements that limit the maximum capacity of a printing plant. Printing production process is complex and has obvious industry attributes. In the process of promoting an intelligent printing plant, exact identification of printing workshop bottleneck processes can effectively help enterprises to find production shortboard. However, there is lack of methods to identify printing production bottlenecks. This paper first uses PlantSimulation software to simulate the printing production process, based on the production data of a domestic packaging printing enterprise. Then, based on genetic algorithm (GA), printing production scheduling with the goal of minimizing the maximum production time is optimized. Under the optimal scheduling condition, in terms of the machine workload (MW), the average uninterrupted active duration (AUAD), and the machine utilization rate (MUR), this paper adopts the multi-attribute decision method to identify the bottleneck of the workshop. The bottleneck equipment and bottleneck processes are determined, and the reasons for the bottleneck is analyzed. Finally, the carton production line is used to verify the proposed method. The bottleneck process is thus optimized in printing production line.