The invention relates to a reagent dosage monitoring device used in a laboratory of the laboratory medicine of a hospital. The device comprises a base; a left side plate is fixedly installed at the upper part of the left end of the base, and a right side plate is fixedly installed at the upper part of the right end of the base; a vertical reagent barrel is fixedly installed at the inner side of the left side plate by means of a first support; an opening is formed in the upper end of the reagent barrel; a piston pillar is arranged in the reagent barrel; a vertical first screw rod is arranged inthe middle of the upper end of the piston pillar, and the lower end of the first screw rod is movably connected with a bearing arranged at the upper end of the piston pillar; a first sleeve sleeves the first screw rod and is fixedly connected with the left side plate by means of a second support; the first screw rod can slide up and down along the first sleeve; a first internal thread sleeve sleeves the first screw rod and is matched with the first screw rod by means of threads. The reagent dosage monitoring device can help medical workers to accurately take reagents, and can effectively avoid the waste of the reagents; furthermore, the reagent dosage monitoring device is not dependent on electric energy, is simple in structure, low in manufacturing cost and convenient to operate, and issuitable for being exported to relatively backward countries with unstable power supply.