The invention relates to a pilot-operated type control air channel system of a breathing machine, which comprises an oxygen communicating pipe, an oxygen flow adjusting valve (NV1), an air communicating pipe, an air inlet one-way valve (DV1), an air flow adjusting valve (NV2), a Venturi device (WENTURI), an air supply control branch air channel and an air supply control electromagnetic valve (CV1). The oxygen flow adjusting valve is arranged on the oxygen communicating pipe, the air inlet one-way valve (DV1) and the air flow adjusting valve (NV2) are arranged on the air communicating pipe, an outlet end of the Venturi device (WENTURI) is communicated with a system external outlet via a main pipe, an inlet end of the Venturi device (WENTURI) is communicated with the oxygen communicating pipe, a bypass of the Venturi device (WENTURI) is communicated with the air communicating pipe, the oxygen communicating pipe is serially communicated with a pressure reduction pump (REG1) and the oxygen flow adjusting valve via air channels from outside to inside, the air supply control electromagnetic valve (CV1) is arranged on the air supply control branch air channel and is serially communicated with the air supply control air channel via an air channel, an inlet end of the air supply control electromagnetic valve is communicated with the oxygen communicating pipe in front of an air inlet end of the oxygen flow adjusting valve via an air channel, an outlet end of the air supply control electromagnetic valve is communicated with a pneumatic control end of the oxygen flow adjusting valve via an air channel, and an exhaust end of the air supply control electromagnetic valve is communicated with the Venturi device or the main pipe via an air channel. The air channel device can adjust oxygen concentration, the small-drift-diameter air supply control electromagnetic valve can be adopted, safety is increased, and the service life of the pilot-operated type control air channel system is prolonged.