Abstract: Dual CCD intersection measurement techniques are used for precise positioning the abrasive surface boundary points of electric locomotives' contact wire, the wire height, stagger values, abrasive width and other geometric parameters can receive non-contact and real-time measurements. The accuracy and resolution of positioning boundary points are limited by optical parameters of the measurement system, the impact of structural parameters, and so on. According to the dual CCD intersection measurement principle, a mathematics model of contact wire geometry measurement was established, the resolution and accuracy of the boundary positions, CCD pixel size, the imaging lens focal length, the distance between the two CCD, the relationship between intersection angle, and other parameters were analyzed in detail, and numerical simulations were made. Based on this, by means of the measurement conditions and technical specifications, the optimization of the parameters was completed, the optimum measurement accuracy and resolution which theoretically can be achieved was obtained, and meanwhile, rational measures were put forward for the production and installation of measuring devices.