The invention belongs to the field of biomass energy conversion, and particularly relates to a biomass fuel furnace feeding mechanism comprising a feeding hopper. The lower end of the feeding hopper is fixedly connected with a vertical pipe, the lower end of the vertical pipe is fixedly connected with a diagonal pipe, a sealing ring is fixedly connected into the vertical pipe, the upper end of thesealing ring is recessed downwards to be arranged in a bowl shape, a sealing block matched with the sealing ring is arranged over the sealing ring, and the lower end of the sealing block is in a round table shape protruding downwards; and the lower end of the sealing block is fixedly connected with a memory spring, the lower end of the memory spring is fixedly connected with a connecting seat, and the connecting seat is fixedly connected to the inner side wall of the vertical pipe through a plurality of connecting rods. According to the biomass fuel furnace feeding mechanism, it can determinethat there is not much fuel remaining in a fuel furnace through the change of the temperature of the position, close to the feeding mechanism, in the fuel furnace, the sealing block is automaticallyjacked upwards, fuel in the feeding hopper can be replenished into the fuel furnace in time, the whole process does not require manual supervision, simpleness and convenience are achieved, and human resources are saved.