The invention provides a non-premixed central air supply multi-tube gas afterburner. A cylinder is a section of metal tube; two end holes of the tube are in closed connection with an air side disk and a flue gas side disk respectively; centers of the air side disk and the flue gas side disk are provided with a through hole; an air nozzle is connected into the through hole in a closed mode and communicated in the length direction; the flue gas side disk is provided with six gas nozzles which are uniformly distributed on a circular ring with the air nozzle as the center; a hole formed at a cylinder position which is not communicated with the air nozzle is in closed connection with a gas inlet tube. According to the non-premixed central air supply multi-tube gas afterburner, the basic structure is simple, the suitable afterburning quantity demand range is large, stable burning can be performed in a high speed flue gas flow area, the temperature is uniformly distributed, the length of a waste heat boiler inlet flue can be shortened, and accordingly the cost is reduced.