The inverse synthetic aperture ladar imaging technique was applied into laser wavelengths and airborne platform, and realized the sparse reconstruction on conical target under micro-motions, with range and azimuth resolution of an order of centimeter. By establishing the imaging model of airborne inverse synthetic aperture ladar, the formations of target′s range distance and ladar echo were analyzed, and the feasibility of detection on conical target by inverse synthetic aperture ladar and airborne platform was verified. Aiming at the problems of high repetition frequency, complex system and data redundancy, a sparse imaging algorithm was proposed based on spatial compressive sensing, to form a linear observation model under the condition of sparse sampling, and transform the imaging problem into an optimization solution of sparse signal on l1 norm organization, in order to realize the reconstruction of target with micro-motions. The experiments of electromagnetic calculation demonstrate the validity of proposed method.