A production method for a water-absorbent resin, comprising a polymerization step for obtaining hydrogel by subjecting a monomer aqueous solution to a polymerization reaction, and a drying step for drying the hydrogel, wherein drying in the drying step is performed using a continuous through-flow belt-type drying machine, the pore opening rate of the through-flow belt in the continuous through-flow belt-type drying machine is 20 to 50%, the solid content of the hydrogel supplied to the drying step is 35% by weight or more, and the area occupancy rate of the hydrogel is 85 to 100% relative to the through-flow belt.