Coking property judgment method based on thermal diffusivity in coking coal pyrolysis process

The invention discloses a coking property judgment method based on thermal diffusivity in a coking coal pyrolysis process, which comprises the following steps of: loading a coal sample (7) into a crucible (2), pressing the coal sample (7) by using a pressure plate (3), and putting the crucible (2) into a bottom heating electric furnace (1), and inserting a thermocouple and a probe (6) in a heat transfer direction from bottom to top in the pyrolysis process; recording the temperature of the upper layer surface of the colloid reaching the lower thermocouple (51) and the temperature of the lower layer surface of the colloid reaching the lower thermocouple and the upper thermocouple (53); and calculating a thermal diffusivity curve at the middle-layer thermocouple (52), wherein in the colloid forming stage, the thermal diffusivity curve is decreased after being increased, and the caking property of the coke is evaluated through the decreasing amplitude, and in the post-curing stage, the thermal diffusivity curve