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.