Aimed at the problem of imaging task scheduling of multifunction phased array radar, this paper puts forward an adaptive scheduling algorithm for ISAR imaging radar based on pulse interleaving. Firstly, the paper calculates the required resources for sparse aperture ISAR imaging according to initial cognition of target feature. On the basis of that, a rational and optimized scheduling model of interleaved pulsedwelling is established, and then radar resources can be allocated reasonably under condition of the dual restraints by time and energy. Average interleaving degree is proposed as an indicator of measuring imaging radar resources scheduling. At last, different targets are imaged respectively by using compressed sensingbased sparse aperture ISAR imaging method, and the required imaging resolution is achieved while the resource utilization rate is enhanced apparently. The simulation result shows that this algorithm is feasible.