Novel premixing internal circulation low-pollutant gas combustion device

The invention discloses a novel premixing internal circulation low-pollutant gas combustion device, relates to the technical field of combustors, and solves the problem that the content of nitrogen oxide initially discharged by an existing gas boiler exceeds the standard. A main flame fuel gas spray pipe is arranged outside a main flame ejection nozzle in a sleeving manner; a plurality of smoke entrainment holes are formed in the main flame gas spray pipe; an air channel necking opening is formed in the end part of the air channel; the end of the on-duty flame gas pipe extends into the gas mixing cylinder, a plurality of on-duty flame short pipes are arranged at the end of the on-duty flame gas pipe, an on-duty gas premixing pipe is arranged in the on-duty flame gas pipe, and the on-duty gas premixing pipe is communicated with the burner air box through an air premixing pipe. Part of air premixing is completed in the on-duty fuel gas premixing pipe, and the burning speed of on-duty fuel gas is increased; the