Abstract: ‍ ‍The detection of low-altitude targets， such as birds and drones， is a current popular research topic under radar detection. Precise individual tracking and observation are required to achieve the recognition of low-altitude target categories and behaviors. Because precise tracking radars lack independent target-acquisition capabilities， the current radar system often adopts a cooperative mechanism in which large-airspace search radars provide indication information， enabling precision tracking radars to capture and track a target. Therefore， high acquisition probability is the key to achieving the efficient observation of low-altitude targets. Existing target-acquisition methods such as parallel scanning， circular scanning， and spiral scanning use a fixed search pattern， which lacks specific optimization for target indication information. To capture low-altitude targets in a limited time， this paper proposes a radar target-acquisition optimization strategy based on variable angular velocity spiral scanning. A method for allocating non-uniform spiral dwell time based on inverse transform sampling is proposed， which optimizes the scanning dwell time at different locations according to the optimal search theory. Subsequently， a supplementary scanning method based on target detection logic is proposed， which effectively improves the target-acquisition probability. Finally， simulation experiments and high-resolution radar system target-acquisition experiments verified the effectiveness of the method.