Measurement method and device for small module gear

The invention provides a measurement method and device for a small module gear, the measurement method is applied to a control system of a multi-sensor gear measurement device, the control system obtains backlight images under the condition that a backlight source is turned on and a light emitting source is turned off, point cloud information of tooth profile edges in all the images is detected and then spliced, and the measurement accuracy of the small module gear is improved. Obtaining first complete tooth profile edge point cloud information; under the condition that a backlight source is turned off and a light emitting source is turned on, light emitting images are obtained, all the images are spliced after being detected, and second complete tooth profile edge point cloud information is obtained; after it is determined that the gear to be measured is installed on the rotating device, the first tooth surface contour point cloud information and the second tooth surface contour point cloud information are o