A bubble continuous positive airway pressure device has a container having an inner space, an inner conduit mounted in the inner space for conducting an airflow, an outer conduit mounted around the inner conduit, a rack longitudinally mounted on the outer conduit, a gear disposed in the inner space and meshed with the rack, and a knobt. The inner conduit has an aperture. The outer conduit is longitudinally slidable relative to the inner conduit, and has at least one through hole connected with the aperture. The knob drives the gear to rotate and the gear drives the rack, so as to drive the outer conduit to slide downward or upward in the inner space. The bubble continuous positive airway pressure device prevents dust and bacteria in the ambient environment from polluting the liquid in the container when adjusting gas pressure, so as to ensure the patients' health.