A burner used for a biomass-gas industrial water heater. The burner comprises: multiple heating tubes (1) arranged in parallel, a thin gas tube (2) used for ignition, a gas valve (3) used for ignition, biomass-gas tubes (4, 12), a biomass-gas valve (5), an ignition nozzle (6), an ignition hole (7), an air feeder (8), blast pipes (9, 11), an air-supply valve (10), and an air-supply hole (13). The thin gas tube (2) used for ignition is at the inner bottom of one of the heating tubes (1) of the burner, and is tightly connected to the heating tube (1). The ignition nozzle (6) is at the inner front end of the corresponding heating tube (1), and is basically on the same straight line with the ignition hole (7). Meanwhile, the air-supply hole (13) is at the tail end of the corresponding heating tube (1). The burner can improve the heating efficiency, is convenient to ignite, and is safe and reliable.
