Disclosed is a medical oxygen mixing valve comprising a valve body, a valve cap, a spring, spool assembly, dial assembly and knob assembly. An axial hole is set inside the valve body. The spool components capable of sliding in an axial direction along the wall of the hole are set in the hole. An air input hole, oxygen input hole and gas mixture output hole which are in communication with the hole are set in the radial direction of the valve body. The knob components are used for adjusting the position of the spool components in the hole set in the axial direction of the valve body to adjust the sizes of the air input hole and oxygen input hole blocked by the spool components, thereby adjusting the output of the oxygen concentration. The oxygen mixing valve has the advantages of a simple structure, and easy machining, installation and debugging.
