Dumper tail door locking device and dumper

The invention provides a dumper tail door locking device and a dumper. The dumper tail door locking device comprises a locking hook and a pneumatic device, wherein the locking hook is hinged to the tail portion of a vehicle body, one end of the locking hook corresponds to a tail door of a carriage, the pneumatic device is arranged on the vehicle body and connected with the locking hook through a connecting rod, the pneumatic device communicates with an air source through a pipeline, when air is injected into the pneumatic device, the connecting rod drives the locking hook to rotate relative tothe vehicle body, the tail door is locked by the locking hook, and when air is exhausted out of the pneumatic device, the tail door is released by the locking hook. By means of the technical scheme,the locking of the tail door of the carriage can be pneumatically controlled; compared with a traditional chain locking mode, locking power is higher, and sealing is tighter; and compared with a hydraulic auxiliary locking dev