<p>PURPOSE: A linear heating device for hydrogen-oxygen mixed gas is provided to prevent backflow of flame caused by user's unintended contact to a base material of a nozzle tip. CONSTITUTION: A linear heating device for hydrogen-oxygen mixed gas comprises a torch(20) which is connected to a fuel supply part and a nozzle tip(30) which is formed on the leading end of the torch to make flame exposed through a flame hole. The nozzle tip comprises a support for maintaining a distance from a base material to be heated. The flame hole of the nozzle tip has a front end diameter smaller than the rear end diameter thereof in order to prevent the backflow of flame.</p>
