This invention provides a drug pressurization delivery device with built-in constant-amount pushing apparatus, it is mainly equipped with a built-in constant-amount pushing apparatus to stably and precisely deliver the drug with introduced compressed air for mixing and pressurizing the drug to spray out for forming atomized injection. The constant-amount pushing apparatus uses bi-directional motor to drive screw to forwardly and reversely rotate the propeller rod for moving forward and backward so that the drug is delivered in syringe delivery tube via a solenoid valve and then delivered to the drug pressurization tube in a constant amount manner through a drug delivery needle tube, which is then mixed with the main air introduced in the drug delivery and pressurization tube for forming the function of air-liquid mixing and pressurization, achieving the high-speed ejection function with precise constant amount and uniform atomization. Moreover, all the components are assembly type and are detachable for cleaning or replacement of damaged and contaminated parts.
