Abstract: Abstract:the disconnector is the most primary power equipment on the power grid, but its defect rate increases year by year with the service life. A non-invasive detection method for motor power of operating mechanism of disconnector is described. On the premise of not damaging the complete structure of the secondary part of the operating mechanism box, the current and voltage signals output by the driving motor are detected on line, the motor power is continuously calculated by the intelligent device, and the time power curve is established. By comparing the power curve with the power curve of the disconnector in the normal state, the mechanical defect degree and position of the disconnector can be diagnosed and verified on the spot.