The invention discloses a novel dry etching method, which comprises the following steps: forming a to-be-etched layer on a semiconductor substrate; forming a masking material on the to-be-etched layer; carrying out dry etching on the masking material and the to-be-etched layer; simultaneously carrying out lateral etching (parallel to the surface of the substrate) of a masking layer and longitudinal etching (vertical to the surface of the substrate) of the to-be-etched layer; and obtaining the inclination angle (the included angle between a slope surface and the surface of the substrate) of the corresponding etched slope surface by accurately controlling the speed ratio. The method can flexibly adjust the inclination angle of the etched slope surface within a large range (0-90 degrees), and especially has advantages in the field of the application with a small inclination angle (smaller than 20 degrees) of the etched slope surface in comparison with a conventional etching method.