Imaging lidars, operating at an active imaging approach, are capable of obtaining high resolution 3D images of objects at far distance even under low illuminance and complicated background conditions, thus it has been an inevitable trend for imaging lidars to be used as mission payloads in the UAS field with extensive application prospects. The types of imaging lidars were summarized and categorized, with technical analysis carried out on relevant research progresses both at home and abroad. On this basis, discussions are made in the view of system design and general structural formats, typical technical architectural options and platform suitability requirements for the UAV-borne imaging lidars were put forward, in combining the features of the UAV-borne environment and in association with comprehensive considerations of the factors as imaging distance, imaging resolution, imaging range and imaging speed (or frame rate) related to typical application situations, with an expectation to provide reference for relevant technology research and equipment development.