In order to achieve the goal of high accuracy and low cost in a visual localization system, we present a novel localization method based on four inexpensive video cameras. The method mainly consists of two parts: The “16-points interpolation algorithm” is proposed to enhance the accuracy of 2D coordinates of the detected target on the image plane. Another important aspect is that the Perpendicular Foot Method (PFM) is used to calculate the 3D coordinates of the target. Simulation and real experimental results show that the stability of image coordinates (x, y) is significantly improved by the “16-points interpolation algorithm”, and the PFM algorithm is better than the traditional LSM (Least Square Method) algorithm. The localization accuracy of this system can reach 5mm, when the target is moved along with the y axes direction which is perpendicular to the optical axes of CCD cameras.