The invention relates to the technical field of focus testing, and particularly discloses a
laser cutting head zero focus testing method based on reflected
light detection, which comprises the following steps: S1, acquiring an optical
signal reflected by a processed plate in a
cutting process; s2, adjusting the position of a focusing lens to enable a
laser focus to move along the
optical axis direction relative to the surface of the plate; s3, recording reflected
light intensity values corresponding to different focus positions, obtaining a function relationship between the reflected
light intensity and the focus positions, and drawing a
light intensity-focus position relationship curve; s4, determining a corresponding focus position when the intensity of the reflected light reaches the maximum value as an optical zero focus position of the
system; s5, automatically recording and storing an optical zero focus position; the reflected
light detector arranged in the
cutting head or the
laser reads the intensity of the reflected light in the cutting process, the function relation between the focus position and the intensity of the reflected light can be established, and the focus position corresponding to the maximum value of the intensity of the reflected light is the most accurate optical zero focus position.