In order to address the lack and inefficiency of teaching tools of the operating system principles course, a VOSLS was proposed. It used Stub method to debug the experimental operating system kernel, and reduce the complex GDB debugging protocols to simple Stub communication protocols. It communicated with the experimental operating system running on a Virtual Machine through the floppy or hard disk image files. Then the running operating system，s information was graphically and vividly delivered to the users by using visualization graphics engine technology. Practice has proved that this system can significantly improve the experimental teaching effect of the operating system principles course.