The invention discloses a closed baffle plate mechanism of a switchgear bus chamber and a power testing device. The invention aims to provide the closed baffle plate mechanism of the switchgear bus chamber and the power testing device, wherein the closed baffle plate mechanism and the power testing device has advantages of convenient operation, effective power testing operation efficiency improvement of the switchgear, and safe and reliable operation. The closed baffle plate mechanism of the switchgear bus chamber comprises a vertical guiderail on the switchgear body of the switchgear, an upper closing baffle plate which is used for blocking the output wiring terminal of the line chamber of the switchgear, a lower closing baffle plate, and a connecting rod mechanism for connecting the upper closing baffle plate with the lower closing baffle plate. The power testing device comprises a base, a closing baffle plate pushing mechanism, an upper-set linked power testing set and a lower-set linked power testing set.