A drug dosing device for dosage metering and control, and a method using the device for metering and control are disclosed. The drug dosing device comprises a drug dosing canister (300), a first flow channel (301), a second flow channel (302), a third flow channel (303), a metering flow channel (304), a switch valve (305), a control valve (306) and a pressure release port (307) the upper part or top of the drug dosing canister (300) communicates with the upper part or top of the metering flow channel (304) via the first flow channel (301) the lower part or bottom of the drug dosing canister (300) communicates with the lower part or bottom of the metering flow channel (304) via the second flow channel (302) the switch valve (305) is disposed on the second flow channel (302) the bottom or lower part of the metering flow channel (304) communicates with the control valve (306) via the third flow channel (303) the pressure release port (307) is disposed at the upper part or top of the drug dosing canister (300) and the cross section area of the metering flow channel (304) is less than the cross section area of the drug dosing canister (300). The drug dosing device and drug dosing process are simplified, thereby saving drug dosage, and reducing the cost and management workload of the drug dosing device.
