Automatic injection pen, assembling jig assembly and automatic injection pen assembling method

The embodiment of the invention discloses an automatic injection pen, an assembling jig assembly and an automatic injection pen assembling method. The automatic injection pen comprises a pen body, a pen container, a pushing injection piston, a locking buckle, a locking hook, a first spring and a second spring. In the assembling process, the locking buckle can move to a locking position from an unlocking position under the action of the first spring and stably stay at the locking position, the situation that when the injection piston is assembled, the locking buckle automatically leaves the locking position, consequently, the piston buckle and the lock hook are separated, and assembling fails is prevented, and the assembling success rate is increased. 本申请实施例公开了一种自动注射笔、装配治具组件和自动注射笔装配方法，本申请实施例包括：笔身笔筒、推注活塞、锁止扣、锁钩、第一弹簧和第二弹簧；装配过程中，锁止扣能够在第一弹簧的作用下从解锁位置运动到锁止位置并稳定停留在锁止位置，防止在装配推注活塞时锁止扣自动离开锁止位置导致活塞卡扣和锁钩脱离而装配失败，提高了装配成功率。