The utility model discloses a passive fiber buss formula electrical manhole cover displacement monitoring system contains: a plurality of monitoring devices installs respectively on each well lid base for monitoring electrical manhole cover's displacement generates alarm signal if electrical manhole cover takes place to remove then to trigger, the surveillance center is connected with a plurality of monitoring devices respectively for receive the alarm signal that monitoring devices sent, wherein adopt optic fibre bus mode to connect between a plurality of monitoring devices. The utility model discloses alarm signal can be sent when electrical manhole cover takes place the displacement, the stolen risk of well lid is reduced to and the cable is stolen in preventing the well.