a drug pressuring and delivering system has an internal quantitative pusher for providing stable and precise drug delivery , and a drug pressuring and delivering device for introducing a compression gas for pressuring and ejecting a drug into an atomized drug . the quantitative pusher adopts a bidirectional motor for driving a screw rod to rotate forward or reversely to push the push rod forward or backward , such that the drug is delivered through a solenoid and a drug delivering needle in a cylinder drug delivering pipe and then quantitatively delivered to a drug delivery pressuring tube . in addition , an introduced mainstream gas in the drug delivery pressuring tube forms a gas - liquid mixing and pressuring action to achieve the precisely quantitative and uniform atomization high speed ejection function . also , all members of the invention can be assembled / disassembled , so that the damaged or contaminated members can be detached , cleaned or replaced .