A cleaning mechanism having a self-locking function, comprising a cleaning rack, a cleaning member and a sweeping member, adapted for use on photovoltaic panel, is disclosed. The cleaning rack comprising a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod which are detachably connected. The cleaning member being detachably mounted between the first connecting rod and the third connecting rod, used for stripping off adhesive materials on photovoltaic panel; the sweeping member used for sweeping adhesive materials away from photovoltaic panel. Cleaning mechanism further comprises a cleaning member power unit, detachably connected with the cleaning member and used for driving cleaning member to rotate; and cleaning member power unit comprises a self-locking device, used for preventing cleaning member from idling, and sundries are prevented from being twisted thereon and meanwhile unnecessary wear between cleaning member and photovoltaic panel can be reduced.