A new measuring system of flexible electronic checking fixture on an industrial robot was proposed to overcome the shortcomings of the real special checking fixtures commonly used in industrial production with high costs, poor flexibility and low automation. A vision sensor was fixed on the terminal tool of the industrial robot taken as the flexible automation platform.By teaching the robot to run the programmed measuring path,the every local sensor system was unified to the global system by global calibration technology.As the repetitive position error of the robot in this process is an important influencing factor on the overall system accuracy, an optical precise measuring method was presented to compensate the whole measuring results in real-time via measuring the repetitive position error by taking another camera as a control camera and combining with global control points fixed on the supporting assembly. Finally,the obtained results were campared with CAD digital module in a computer to realize the virtual flexible checking fixture function. Experimental result indicates that the overall three-dimensional root mean square (RMS) error of fourteen space points is 0.101 mm,which shows that the principle of method is reasonable. It overcomes the limitation of real checking fixture in high cost, heavy waste and accuracy affected by personal errors.