Gas premixing device and flow control method thereof

The invention discloses a gas premixing device and a flow control method thereof. The gas premixing device comprises a base, and the first end of the base is connected with a first gas inlet pipe connector. The second end of the base is connected with a second gas inlet pipe connector. The third end of the base is connected with a premixed gas outlet pipe connector, a rotary cavity is formed in the base, a center body is axially arranged in the rotary cavity, a gas circulation channel is formed in the center body, a gas collection cavity for first gas and an axial annular channel for generating injection pressure drop are formed between the center body and the base, and the first gas inlet pipe connector communicates with the gas collection cavity. A plurality of radial spraying holes are circumferentially and uniformly distributed in the second end of the center body at the tail end of the axial annular channel and are used for forming injection pressure drop, and second gas enters the gas circulation channe