The invention discloses a heavy metal pollution plot remediation device, and relates to a multi-component material fine mixing device. The device comprises a feeding hopper, a feeder, a lifting device, a chemical filling machine, a mixer, a single-carrier-roller belt conveyor, a dust collector, a moving flat trolley and a PLC control system; the feeding hopper comprises a feeding hopper body, andthe feeder is located below a feeding part and is a belt-type quantitative feeder; the chemical filling machine is located above the feeder; the lifting device is located above the chemical filling machine, and an outlet of the chemical filling machine corresponds to the feeder; the mixer comprises a mixing box, a cutting shaft and a mixing shaft, the cutting shaft and the mixing shaft are arranged in the mixing box, the cutting shaft is provided with cutting wheels, and the mixing shaft is provided with mixing wheels; the lower portion of the mixing box is provided with an outlet, and the single-carrier-roller belt conveyor is located below the outlet of the mixing box. The heavy metal pollution plot remediation device has the functions of winding prevention, crushing and multi-stage impact mixing, soil can be fully mixed with a chemical, the influence of pollutants on equipment performance due to difference of the particle size, hardness and humidity is reduced, the energy consumption is low, and the use effect is good.