The invention discloses a safety valve and a breathing apparatus. The safety valve comprises a base, a driving part and a quick release assembly, wherein the quick release assembly comprises a main airway, an autonomous breathing airway and an opening and closing part, wherein the autonomous breathing airway extends to the outside of the safety valve in a sealed manner and is communicated with an external environment; the main airway and the autonomous breathing airway are both arranged on the quick release assembly, so that airflow is isolated from the base and the driving part and is completely not contacted with the base and the driving part, and the condition that air in the autonomous breathing airway moves to the base, the driving part or other parts in the breathing apparatus and pollutes the parts is reduced or completely eliminated. Furthermore, the quick release assembly taken as a part, directly contacted with air, in the safety valve can be dismounted from the base conveniently, and is disinfected and sterilized independently and easily.