A quick battery case replacement system, the quick battery case replacement system comprises a battery holder and a battery case, the battery case comprises a battery case unlocking apparatus, the battery case unlocking apparatus comprises a locking mechanism ; the locking mechanism is used for locking and fixing a body of the battery case to the battery holder of an electric vehicle; wherein, the battery case unlocking apparatus further comprises a mount , an extensible/retractable mechanism and a transmission mechanism ,the extensible/retractable mechanism passes through the mount and carries out extension/retraction movement in the mount relative to the transmission mechanism under an unlocking external force; the transmission mechanism is connected with the extensible/retractable mechanism at one end, and the other end of the transmission mechanism is connected with the locking mechanism ; the extension/retraction movement of the extensible/retractable mechanism drives the transmission mechanism to move between the extensible/retractable mechanism and the locking mechanism , and the movement of the transmission mechanism controls the locking or unlocking of the locking mechanism ; wherein, the transmission mechanism comprises an active pole , a driven pole , a connecting rod , a driving rod and a guiding part ; the active pole is connected with the extensible/retractable mechanism , the driven pole is connected with one end of the driving rod , the connecting rod is connected with the active pole and the driven pole respectively, the connecting rod may rotate around the axis of the active pole , and the connecting rod may rotate around the axis of the driven pole ; the other end of the driving rod is connected with the locking mechanism ; the guiding part is provided with a driven guiding hole extending along the moving direction of the driving rod , and the driven pole passes through the driven guiding hole and slides in the driven guiding hole ; the guiding part is provided with an active guiding hole extending along the extending/retracting direction of the extensible/retractable mechanism , the active pole passes through the active guiding hole and slides in the active guiding hole . the extension/retraction movement of the extensible/retractable mechanism drives the transmission mechanism to move between the extensible/retractable mechanism and the locking mechanism , and the movement of the transmission mechanism controls the locking or unlocking of the locking mechanism ; wherein, the transmission mechanism comprises an active pole , a driven pole , a connecting rod , a driving rod and a guiding part ; the active pole is connected with the extensible/retractable mechanism , the driven pole is connected with one end of the driving rod , the connecting rod is connected with the active pole and the driven pole respectively, the connecting rod may rotate around the axis of the active pole , and the connecting rod may rotate around the axis of the driven pole ; the other end of the driving rod is connected with the locking mechanism ; the guiding part is provided with a driven guiding hole extending along the moving direction of the driving rod , and the driven pole passes through the driven guiding hole and slides in the driven guiding hole ; the guiding part is provided with an active guiding hole extending along the extending/retracting direction of the extensible/retractable mechanism , the active pole passes through the active guiding hole and slides in the active guiding hole . <EOS>