The invention discloses a recyclable vehicle-mounted head up display which comprises a light source, a reflecting device, a movable support, a dustproof device, a sliding block, a sliding block rail and a box body. The dustproof device is of a telescopic structure, and the length of the dustproof device is controlled by spreading or contracting the dustproof device. The movable support, the sliding block, the sliding block rail and the light source are mounted and fixed in the box body, the sliding block is mounted on the sliding block rail and can move relative to the sliding block rail, and thus the dustproof device is driven to retract or rotate. The reflecting device is mounted on the movable support, and the movable support can rotate relative to the box body to move between at least one rest position and at least one display device. Correspondingly, the invention further discloses a vehicle adopting the recyclable vehicle-mounted head up display. Through the adoption of the recyclable vehicle-mounted head up display and the vehicle, dust can be prevented, the size is small, little vehicle space is occupied, a good display effect is achieved, and the sight of a user is not influenced.