The invention discloses a material level measurement device. A fluidizing device is arranged at the bottom of a hopper to make a material in the hopper be in fluidization. The material level measurement device comprises at least one measurement pipeline, wherein the measurement pipeline and the hopper are communicated with a preset material level and is further provided with a pressure measurementcomponent for measuring pressure of the material at the preset material level. The material level measurement device further comprises a blowing component used for blowing air into the hopper to separate the measurement pipeline from the material in the hopper. When the material level measurement device disclosed by the invention works, pressure measured by the pressure measurement component is pressure of the actual stacked material at the preset material level; thus, effects of complex material characteristics in a circulating fluidized bed dry desulphurization dust remover ash hopper to measurement results are smaller, and relatively accurate real-time material level measurement can be achieved. The invention further discloses a material level measurement method.