The invention relates to a combustor for industrial furnace heating, in particular to an adjustable pure oxygen combustor. The adjustable pure oxygen combustor comprises an oxygen gas nozzle and a fuel gas nozzle; an oxygen gas channel is formed inside the oxygen gas nozzle; at least two fuel gas channels are formed inside the fuel gas nozzle; the oxygen gas channel is connected to an oxygen gas supply pipe; the fuel gas channels are at least divided into two sets, each fuel gas channel is connected to a fuel gas supply pipe through a pipeline, and at least one pipeline connected to one set of the fuel gas channels is provided with an adjusting valve; the adjusting valve is used for adjusting the proportion of the fuel gas supply quantity inside each fuel gas channel. According to the adjustable pure oxygen combustor, on the condition that the total quantity of fuel gas and oxygen gas is unchanged, the flame length can be adjusted for realizing the optimal heating effect, energy conservation and emission reduction can be realized, the quality of heating products can be improved, the operation safety of furnaces can be guaranteed, and the service life of furnace equipment can be prolonged.