The invention relates to the field of polysilicon purification, in particular to a polysilicon directional solidification device which comprises a furnace body, a quartz crucible is placed in the furnace, a graphite heating unit, an insulating sleeve and a induction coil are arranged on the outer wall of the quartz crucible from inside to outside in sequence in a surrounding manner, an ingot mechanism communicated with the bottom of the furnace body is arranged at the bottom of the quartz crucible, the height of the insulating sleeve is 1.5 to 2 time higher of that of the quartz crucible, a graphite spiral plate is arranged at the upper part of the ingot mechanism, a spiral channel built in the graphite spiral plate is communicated with the inlet of the ingot mechanism, and outlets are formed in the edge of the two sides of the graphite spiral plate. According to the device, thermal radiation of the sidewall of the quartz crucible generated in the pulling process can be better intercepted, thermal radiation of the sidewall of the quartz crucible is effectively decreased, and the directional solidification effect is better than conventional solidification method. The device is short in warming up time, small in insulating energy consumption, controllable in cooling speed, the crystal growth is better in cooling method when compared with conventional mode, and can better realize directional solidification effect.