Operating systems play an important role in modern life. To serve different hardware environments and diverse application scenarios, they need to be scalable and flexible while maintaining good performance. A multicore operating system, as a kind of distributed operating system, is one of the solutions to this problem. This study analyzes the design principles of multicore operating systems, investigates existing multicore operating system technologies, and compares these technologies with other relevant ones. Finally, the current situation and trend of the research on multicore operating systems are summarized.