The invention provides a multi-spray-nozzle bulky combustion low-NOx gas combustor, which comprises a heat insulation tile, a first-stage combustor, a second-stage combustor, a first-stage fuel distribution pipe and an air box, wherein a first passage and a second passage are arranged on the heat insulation tile, the lower end of the heat insulation tile is connected with the upper end of the air box, in addition, the first passage is communicated with a cavity of the air box, the first-stage fuel distribution pipe is arranged in the first passage and the cavity of the air box, the second-stage combustor is arranged in the second passage, the top end of the first-stage fuel distribution pipe is provided with a hemispherical sealed surface, the tail end of the first-stage combustor is arranged on the hemispherical sealed surface, and in addition, the inside of the first-stage fuel distribution pipe is communicated with the inside of the first-stage combustor. The multi-spray-nozzle bulky combustion low-NOx gas combustor technically synthesizes fuel grading, smoke gas recirculation and multipoint bulky combustion control techniques, and has the characteristics that long flame in multipoint bulky combustion can be formed, the peak temperature of the combustion flame is reduced, the distribution of heat loads in a furnace is uniform, and the generation amount of NOx is ultralow.