After analyzing the basic composition and principles of multicolor printing system, we presented a design of real-time monitoring system for printing registration based on multitask real-time operating system μC/OS-Ⅱ. According to functional requirements of registration system and the target development platform, we described the detailed process of task division, priority assignment, and synchronization and communication, and optimized the real-time performance of system in the premise of stability assurance. Finally, the feasibility and effectiveness of the system were proved by the good performance of registration runtime system in factories.