Disclosed an intelligent vehicle speed measuring device and method. The intelligent vehicle speed measuring device comprises an image collecting module, a storage module, a display module, a video processing module and an alarming module. The image collecting module collects colored video image information and transmits the same to the storage module, the display module and the video processing module at the same time, the display module displays actual highway traffic information in real time, the storage module is used for storing realtime video information for archiving and recording, and the video processing module performs speed measuring detection on the video information, detects to acquire vehicle overspeed information, displays and alarms through the steps of background modeling, front-ground detection, speed measuring line setting, vehicle information matching and updating, overspeed detection and alarming. By the intelligent vehicle speed measuring device and method, reliable vehicle speed measuring and realtime alarming can be realized, traffic managing personnel is assisted to timely handle overspeed conditions, traffic accidents are prevented, and traffic safety is guaranteed intelligently while traffic order is maintained.