Computer case locking device

The invention relates to a computer case locking device which comprises a base, a cover plate arranged on the base and an unlocking structure arranged on the cover plate, wherein the base is provided with a fixing and holding slot and a fixing and holding part; the cover plate is provided with a barb matched with the fixing and holding slot and an elastic fixing arm buckled with the fixing and holding part so as to limit the movements of the cover plate in different directions and fix the cover plate on the base; the unlocking structure is provided with a butting part butted against the elastic fixing arm; and the butting part can be butted against the elastic fixing arm by operating the unlocking structure to ensure that the elastic fixing arm is separated from the fixing and holding part on the base so as to open the cover plate.