The invention discloses an automatic release device of an unmanned aerial vehicle parachute and relates to the technical field of separation and release devices. The automatic release device aims at solving the problem that the automatic release device of the unmanned aerial vehicle parachute in the prior art causes damage to unmanned aerial vehicle equipment easily. The automatic release device comprises a hook, an upper housing, a lower housing, an upper lock cylinder and a telescopic needle. The top end of the hook is connected with the parachute, the bottom end of the hook is connected with the top end of the upper housing, the lower housing is in butt joint with the upper housing, the upper lock cylinder is arranged in the upper housing and the lower housing, an upper shaft is arranged in the top region of the upper lock cylinder, and the position between the upper shaft and the top end of the hook is connected and sleeved with a parachute rope. The telescopic needle is arranged in the upper lock cylinder and located under the upper shaft. One end of the telescopic needle is in clamped connection with the lower housing, the other end of the telescopic needle abuts against the inner wall of the upper housing, and the outer side of the telescopic needle is sleeved with a telescopic needle spring. The automatic release device is mainly applied to manufacturing of unmanned aerial vehicles.