A bubble continuous positive airway pressure device has a container (10), an inner conduit (21) for conducting an airflow, an outer conduit (22), a rack (31), a gear (32), and a knob (331). The inner conduit (21) has an aperture (2121). The outer conduit (22) is longitudinally slidable relative to the inner conduit (21), and has at least one through hole (221) connected with the aperture (2121). The knob (331) drives the gear (32) to rotate and the gear (32) drives the rack (31), so as to drive the outer conduit (22) to slide downward or upward in the container (10). The bubble continuous positive airway pressure device prevents dust and bacteria in the ambient environment from polluting the liquid in the container (10) when adjusting gas pressure, so as to ensure the patients' health.