The invention discloses a material locking and anti-backfire device for a household biomass boiler. The material locking and anti-backfire device comprises the boiler, a smoke outlet is formed in thecenter of the left end of the boiler, stop blocks are installed on the upper side and the lower side of the outer wall of a rotating rod, a handle is installed at the center of the top of the front face of a boiler door, a second supporting rod is installed at the center of the left end of a round block, a magnetic block is installed at the left end of the second supporting rod, a magnetic groovesleeves the outer wall of the magnetic block, a buckling groove is formed in the outer wall of the magnetic groove, a threaded block is installed at the bottom of the third supporting rod, the rear portion of the threaded block is connected with the center of the bottom of the front face of the boiler, and the center of the outer wall of the threaded block is in threaded connection with the thirdsupporting rod through a threaded rod. According to the material locking and anti-backfire device for the household biomass boiler, the size is large, when the biomass waste combustion operation needsto be carried out, through the cooperation between the boiler and the smoke outlet, the boiler can be sealed, and then the situation that due to the fact that the boiler generates backfire, workers are scalded is effectively prevented.