A non-contact and optical measuring automation system includes a base, a rotating chuck to clamp a disk cam, a moving stage module and an optical measuring module. The moving stage module includes a first linear motion stage movably disposed on the base, a second linear motion stage movably disposed on the first linear motion stage, and a rotary motion stage rotatably disposed on the second linear motion stage. The optical measuring module disposed on the rotary motion stage includes a laser-emitting unit and an image-capturing unit. The laser-emitting unit projects a light beam onto a cam surface of the disk cam, and the image-capturing unit receives scattering light to capture a grayscale measuring image including a profile speckle pattern. A computer calculates a profile speckle characteristic value according to the grayscale measuring image and the surface roughness value according to the profile speckle characteristic value.