The LT-H10 hobbing machine numerical control system is an embedded system based on ARM processor. The CPU occupancy in ARM-based NC system is always higher than that in x86-based systems for some characteristic of ARM processor itself limits. A μC/OS-II system porting scheme based on MicroBlaze soft-core processor is presented in this paper, to reduce the occupancy of ARM processor by executing some driver programs of master station on the MicroBlaze soft-core processor of FPGA chip on the bottom plate. The experimental test results show that the μC/OS-II system ported on the MicroBlaze processor can run stably. The rapid context-switch benefits to the real-time of the NC system. We design two different tasks scheduling algorithm to measure and research the context-switch time in MicroBlaze-based μC/OS-II system and ARM-based Linux system. This study can not only meet the application needs of CNC system based on ARM, but also can been applied to CNC system based on X86, to achieve the purpose of reducing CPU occupancy, which has important research meaning and application value in Embedded CNC system.