A kind of design method of low voltage power quality monitor based on real time operation system（RTOS） is introduced in this paper.According to demand of power quality monitoring of low voltage distribution system

RTOS is reduced

modified and transplanted to CPU as the developing and running platform of system software.Task functions are implemented based on this software platform.The experiment results prove that the power quality monitor based on real time operation system has good performance of real-time ability

stabilization and reliability.