The main purpose of this research is to construct a low-cost optical dynamic gait pressure measuring system. The phenomenon of image deformation as well as the intensity uniformity is the key issue to the measurement system. The correction algorithms have been developed. A webcam is used to capture the measuring image and followed by image processing to obtain the gait pressure distribution information. This components used in this research are chosen from off-the-shelf components. The main structure is made by aluminum bar and acrylic. The webcam will catch the movement who walk on the measurement platform and the gait pressure will show on the image files. The image combines the color identify table to show the pressure measurement diagram. The size of foot pressure gait machine is 900 × 660 × 280 mm, the maximum measuring range is 840 × 600 mm and the resolution is 10.8 sensors/cm2.