Background: At present, there are few breathing circuits that can protect health care workers. Here, we have developed a new disposable medical protective sputum suction breathing circuit.Methods：The main components of the structure of the novel medical protective breathing circuit are adapter, isolation sleeve, stop sleeve, sealing cover and sealing ring. An isolation sleeve is inserted into the conversion joint. The isolation sleeve inner sleeve has a stop sleeve with an inverted round table structure. The upper nozzle of the adapter is provided with a sealing ring tightly combined with the lower outer edge of the isolation sleeve, and a sealing cover is provided on the sealing ring.Results: The device is easy to operate and can prevent the pollution caused by sputum splashing when sucking sputum.Conclusion: The medical protective sputum suction and breathing circuit is simple in structure, easy to use, and can effectively protect medical staff.