The invention discloses a self-adaptive closed-loop control flying optical path mechanism and a control method thereof. The flying optical path mechanism comprises a laser, a flying optical path and a drive control system; the flying optical path comprises a flying focusing head and a binocular system; the binocular system comprises an eyepiece and an object lens; the flying focusing head comprises a plane mirror and a focusing mirror; the laser and the eyepiece are relatively fixedly arranged; light beams which are emitted by the laser are reflected to the focusing mirror for focusing by sequentially passing through the eyepiece and the object lens; and the drive control system can drive the object lens and the focusing mirror to carry out the reciprocating motion along an optical axial line according to the position signals of the flying focusing head and the focusing mirror. The flying optical path mechanism has high-performance self-adaptability, and can improve the focusing feature of the flying light beams, accurately and reliably compensate the change of the depth of focus of a laser focus point and obtain the set focus size and the depth of the focus through controlling the positions of the beam expanding object lens and the focusing mirror along with the change of the flying distance; furthermore, the method is simple and reliable, a complicated control unit of a deformable mirror is eliminated, the structure is simple, and the cost is low.