The invention relates to the technical field of pen-type injection devices, in particular to a self-driven automatic
injection device which comprises a shell, a
medicine bottle support, a driving device and a control device. A
needle puncture-proof protection
assembly is arranged on the lower portion in the shell, the
needle puncture-proof protection
assembly comprises a needle hiding sleeve, and the
needle puncture-proof protection
assembly is configured in the mode that in the injection process or after injection is completed and the needle hiding sleeve is pulled out, the needle hiding sleeve can be locked, and then injection cannot be continued; an
energy storage locking assembly is arranged on the upper portion of the interior of the shell and is configured in the mode that before injection, the driving rod is locked by the needle hiding sleeve, when one end of the needle hiding sleeve is stressed to move towards the driving rod, the driving rod is unlocked, the torsional spring provides driving force to enable the driving rod to drive the push rod to move towards the
medicine bottle, and injection is achieved. Stable and reliable injection power can be provided, and injection can be rapidly achieved; in addition, the needle hiding sleeve can be locked no matter the needle hiding sleeve is pulled out during injection or after injection is completed, so that the needle hiding sleeve does not retract inwards, secondary injection is prevented, and safety and reliability are achieved.