Robotic assembly is an important process to replace manual picking in industrial smart manufacturing. One of the important steps in assembly is robotics grasping and sorting of the workpiece. In this paper, a lightweight visual epigynous system was designed to address sorting workpieces with high efficiency, portability, and accuracy. The software of the system was divided into a vision calculation module (VCM), an ethernet communication module, a system control module, and a real-time display module. VCM is responsible for obtaining the information of workpieces, which includes segmenting the images captured by the webcam sequentially and recognizing the digit, and calculating the angle by algorithms of AKAZE feathers matching with and orientation estimation for vector comparison. The proposed method in VCM performs best in estimating the orientation of the workpiece through the comparison of different template matching algorithms. The industrial field experiments indicated that the robot could satisfy the requirement of visual sorting. This system provides a practical and robust solution for industrial workpiece sorting applications.