泵动式（Pump-action），是一种枪的运作方式。它是指通过一根可以移动的护木，通过一根传动杆连接由射击者直接驱动枪的枪机前后运动，从而完成射击循环的运作方式。在使用一只泵动式枪时，应先扣下扳机，待枪发射后用力向扳机方向将护木拉到底，看到弹壳抛出并听到“咔嚓”一声后，再用力将护木向枪口方向推到底，即可完成上膛而再次准备发射。

泵动式枪与其他的常见枪的结构比起来并没有很大的不同，在这些枪支中都是由枪机的往复运动完成射击循环，不同的是泵动式枪支的枪机直接与护木相连，而不存在诸如活塞这类自动射击循环所需的活动部件。

A pump-action rifle or shotgun is one in which the handgrip can be pumped back and forth in order to eject a spent round of ammunition and to chamber a fresh one. It is much faster than a bolt-action and somewhat faster than a lever-action, as it does not require the trigger hand to be removed from the trigger whilst reloading. When used in rifles, this action is also commonly called a slide action. The 40mm M203 grenade launcher mounted under the barrel of M16 rifles and M4 carbines is sometimes described as "pump or slide-action." It is not. Once fired, the barrel is slid forward by hand and the expended cartridge ejected. It is then hand reloaded by manually inserting a cartridge into the chamber and the barrel slid to the rear to arm the weapon. The reloading process does not involve mechanically reloading from a magazine.