Optical measuring system

The present invention relates to an optical measuring technique, and more particularly, to an optical measuring system including a jig for holding a workpiece to be measured, an optical measuring apparatus and a grating ruler, wherein the optical lens of the optical measuring apparatus faces the workpiece to be measured and the optical measuring apparatus is fixedly arranged on a sliding device. The moving direction of the optical lens along the sliding device is also in the length direction of the workpiece to be measured; the length direction of the grating ruler is parallel to the moving direction of the sliding device. The optical measuring apparatus and the grating ruler are connected to a computer respectively. The use of the sliding device enables the optical measuring apparatus to move and take pictures for multiple times. The applications installed in the computer can process measured data so that measurement can be available to workpieces with great lengths. With a simple structure, the system is al