The paper deals with a problem of noise reduction for drone detection with high range resolution radars. The considered discrete clutter includes land vehicles, birds, etc. This clutter involves in the radar echo signals and could not be rejected by using classical methods, for example moving target indicator (MTI) and moving target detection (MTD). As a result, this clutter forms the false alarms on the radar screen. To reduce clutter we propose a new method which is based on the target’s Doppler dispersion and moving characteristic. The study is integrated on a drone detection radar and is tested with a variety of drones in different moving scenarios. The test results show that the proposed method achieves a better performance than that one recently published.