Abstract: To mitigate the impact brought about by scheduled outage in 10 kV lines of distribution networks on power supply reliability of medium-voltage users,this paper uses time slice to establish a power supply reliability analysis model for scheduled outage.By dividing standard operation links of a scheduled outage event with time slice,the paper calculates impact coefficients of operation links with power outage and assesses the rationality of scheduled outage time by analyzing the change law of power supply reliability index under disadvantage factors.The results of this study can be applied to assess vulnerable links of power supply reliability and provide a data reference for power supply reliability management.