A two-dimensional numerical control (NC) X-Y table control system is designed based on STM32 and uC/OS-II. For good real-time capability and stability of the system, embedded STM32F103VET6 is used as a control center. Real-time operating system uC/OS-II is used. Communication modes among tasks are designed. Resources of software and hardware are managed centrally. So the performances of the system are improved. Simple G code input is supported by the design, and the G code is programmed to realize linear and circular interpolation of stepping motors on NC X-Y table. So plane contour processing is finished and real-time capability and stability of NC table processing are further improved.