A dynamic measuring method for combining the laser light curtains and CCD is proposed to achieve a precise measurement of the vehicles outside dimensions. Rapidly acquisition image of the laser spot light curtain is modulated by vehicles height with CCD cameras mounted gantry vertex, and extract the vehicle distribution data of the edge based on region growing centroid matching algorithm to measure vehicle width. Secondly, a sequence of images with mosaic method is used to get the vehicle panoramic image, and pinpoint the front and rear of vehicle by panoramic image projected first-order differential, then depending on the camera perspective model to measure the length of the vehicle, combined with a width edge distribution data to correct the length accuracy. Obtain infrared light curtain vertically mounted projection data via FPGA processing system to measure vehicle height. The measurement method have the advantages of a space occupied by small, simple installation structure, strong anti-jamming capability and high accuracy measurements compared with traditional measurement methods of laser radar and infrared light curtain. The results of the outer contour of the vehicle size measuring test show that the measurement system error is <1% and the average time-consuming is lower than 50 s. Verify the accuracy and real time of this measurement method, and this measurement method is robust and important applications.