In recent years, with the improvement of automation technology in my country, factory automation has also reached a new level. As an emerging industrial controller, the PLC (Programmable Logic Controller) has unique advantages such as small size, complete functions, low price, and high reliability, and has been widely used in various fields. As the largest printing press manufacturer in China—Beiren Group—we adopted a control scheme based on PLC as the main controller to ensure stable product performance and ease of maintenance. Because the two-color printing press requires ease of operation and high precision, it has many input and output points, therefore a dual-machine communication system was adopted. The upper-level computer uses a Mitsubishi FX2N-80MR+32EX+4D/A, mainly responsible for the control of the main drive, the clutch pressure control of each unit, and the control of air pumps and valves. The lower-level computer uses a Mitsubishi FX2N-64MR+4A/D, mainly responsible for the control of the water roller motor, the speed control output of the main drive, and the data acquisition of the plate adjustment motor. A Mitsubishi 5.7-inch touch screen was also selected, mainly responsible for displaying the water roller motor speed, plate adjustment display, and overall machine fault display. This system is reliable, easy to maintain, and simple and intuitive to operate, greatly improving the quality of offset printing machines and receiving high praise from users. The upper and lower computers use RS485 communication, which is convenient and reliable. For multi-color printing presses, safety is paramount. The design of each unit must consider both safety controls (including emergency stop and safety buttons) and ease of operation (including positive and negative buttons for each unit). This results in a significant increase in input points and inconvenient wiring. Using dual-machine communication effectively solves this problem; the wiring of each unit can be routed to the nearest control cabinet, saving wiring and facilitating control. Since printing presses are high-precision machines, the quality of printed products depends on the precision of machining and installation, as well as the balance and accuracy of the water and ink circuits. Each color group of a two-color press has water and ink circuit devices. To facilitate the adjustment of the water roller speed, each water roller is controlled by a frequency converter, and the main motor speed also requires frequency converter adjustment. Therefore, to achieve multi-channel speed adjustment, we adopted a Mitsubishi 4D/A digital-to-analog converter (DAC). This converter converts the digital signals from the PLC into a 0-10V DC voltage output according to a corresponding algorithm, effectively fulfilling the requirements for multi-channel speed adjustment. In the printing process, plate adjustment is a relatively tedious process. Especially for multi-color presses, the alignment accuracy of each plate group has a significant impact on the printed product. If the registration is inaccurate, overlapping text or unclear images will appear on the printed product. Generally, the axial adjustment range of the printing plate is -2mm to +2mm, and the circumferential adjustment range is -1mm to +1mm. Manual plate adjustment is time-consuming and lacks precision. To achieve automatic plate making, we installed potentiometers on the plate rollers. These potentiometers transmit analog signals to the 4A/D converter, which, after processing by the PLC, allows for precise control of the plate roller rotation accuracy within the plate making range. Touchscreens, as a new type of human-machine interface, have attracted attention since their inception. Their ease of use, powerful functions, and excellent stability make them very suitable for industrial environments. Users can freely combine text, buttons, graphics, numbers, etc., to process or monitor and manage information that may change at any time. With the rapid development of machinery, traditional operating interfaces required skilled operators, hindering efficiency. However, human-machine interfaces (HMIs) clearly indicate and inform operators of the machine's current status, making operation simple and intuitive. Using touchscreens also standardizes and simplifies machine wiring, reduces the number of I/O points required for PLC control, lowers production costs, and relatively increases the added value of the entire system. Mitsubishi touchscreens and Mitsubishi PLCs have excellent versatility, allowing for online monitoring and program modification without the need for cumbersome repeated plugging and unplugging of interfaces.