Multi-cavity gas and air mixing device

A multi-cavity gas-air mixing device includes at least two mixing cavities each having an air inlet and a mixture outlet communicated with a combustor, wherein each of the mixing cavities has a built-in gas pipeline, each of the gas pipelines is provided with a gas jet, and the orientation of the gas jet is intersected with a flow direction of air entering into the mixing cavities. The device effectively segments the gas-air mixer and achieves a large load regulation ratio, without producing condensate water at any load segment, thereby improving the system reliability and service life. The built-in gas pipeline not only actively controls the fuel in the open-close control pipeline, but also reduces the volume of the mixer and largely decreases the cost.