The invention discloses an accurate and quantitative dry powder medicament dosing system, which is composed of a medicament storage box, a vibrator, a stepping drive device, a screw conveying device, a rubber waterproof plug, a cylinder, an air blowing pipe, a material sensor and a PLC control module. The sensor and the material sensor are respectively arranged at both ends of the medicine storage box. The outlet of the medicine storage box is vertically connected to the screw conveying device. For screw transmission, the delivery outlet of the screw delivery device is connected by a rubber waterproof plug, which is installed on the cylinder, and the upper end of the delivery outlet of the screw delivery device is provided with a blowing pipe, and the agent is added through the blowing pipe. The system can realize dry powder Accurate and quantitative dosing of chemicals, real-time adjustment of dosage, alarm for lack of material, automatic waterproof and moisture-proof when shutdown, etc., is a new type of precise dry powder chemical dosing system.