The invention discloses a preparation method of an industrial silicon smelting reducer. The preparation method comprises the steps of uniformly mixing blind coal, a binder, various types of carbon powder and biomass to obtain a mixed material; adding the prepared mixed material in batches into a material bin of a molding machine, fully stirring in the material bin and slowly heating to the temperature of 80 DEG C to 300 DEG C, allowing the material to enter a pellet pressing system by the effect of the gravity of the material, and then performing a hot-press molding process to prepare pellets of which the sizes are from 150mm to 600 mm; rapidly demolding and drying the obtained pellets through cooling and scouring of water; adding the cooled and scoured pellets in batches into an industrial silicon ore-smelting furnace to replace charcoal to produce a high-quality industrial silicon product. An industrial silicon pellet reducer produced by the preparation method disclosed by the invention has the characteristics of high fixed carbon content, low ash content, good reaction activity, large porosity, proper particle size, high mechanical strength and the like, the yield can be increased, the product quality can be improved, the power consumption can be reduced, and the production cost can be lowered, so that the preparation method is suitable for smelting of industrial silicon of medium and large ore-smelting furnaces.