The invention discloses a dustproof sieving device for a powder material for a chemical experiment. The dustproof sieving device comprises an outer shell, a horizontal arrangement plate, a horizontalsliding plate, a sliding sleeve, a swing sleeve, a fixed rotary shaft and a motor. The horizontal arrangement plate, the horizontal sliding plate, the sliding sleeve, the swing sleeve, the fixed rotary shaft, a dust hood, an air pipe, an air pump and a dedusting box are arranged on the outer shell. The horizontal arrangement plate is provided with a sliding clamping groove and a supporting roller.The horizontal sliding plate is provided with a limiting protrusion, a limiting spring, a rack and an upper oblique block. The sliding sleeve is provided with a sliding rod, a lower oblique block, areset spring and a sliding rotary shaft. The swing shaft is provided with a sieve box, a rotary horizontal arrangement plate and a movable supporting part. A sector gear, a swing rod and a sliding groove are arranged on the periphery of the fixed rotary shaft. The motor, a rotary rod and a sliding protrusion are arranged at the upper end of the outer shell. The horizontal sliding plate swings leftand right on the horizontal arrangement plate, thus, the sliding rod drives the swing sleeve to swing left and right, the sieving efficiency is improved, and dust flying is avoided by additionally arranging an air pump and the dedusting box.