In reverse engineering, it is very challenging to acquire the 3D profile information of an object rapidly with high accuracy. This becomes even harder to measure the profile of a large object, such as an automobile body press part as it has a wide scope and is not easy to realize. A new non-contact measuring method using multi structure linear lighting (or multi light-knife) based on laser scanning measurement technology is presented in this paper. The principle of the multi light-knife is first presented. To improve the accuracy of the measuring device developed in this work, a virtual net mapping and the least square theory is applied to calibrate the measuring device of the multi light-knife in the whole measuring field. When the device is used to measure automobile body press parts, a route planning method is used to ease the contradiction between measuring accuracy and the range of measurement. System calibration is achieved by compensating the platform error. Experiments on a rear view mirror case show that the multi light-knife is a very effective device and can become a very promising way to acquire the 3D profile information of large objects. r 2003 Elsevier Ltd. All rights reserved.