A railway geometry parameters measurement system on the basis of the vidometrics theory is designed. The system consists of two components a measurement bogie and a target bogie. When the measurement procedure is preceded, the target bogie moves towards the measurement bogie along a rail. The camera on the measurement bogie grabs the motion image sequences of the infrared cooperative markers on the target bogie in a real-time manner. At the same time, the software installed in the industrial computer on the measurement bogie locates the sub-pixel positions that the cooperative markers project into the image sequences, and it drives the motorized lens to the correct imaging state according to the distance between the markers and the image definition. Consequently, the viewing field of the camera holds the line and the images of the markers remain definite. Finally, the railway geometric parameters are synthesized from the positions of the markers on the basis of corresponding mathematical model. Both the static and the field experimental results prove that this videometrics measurement system can satisfy the requirement of the high-precision measurement for the rail geometric parameters.