For effectively acquiring object 3D surface data to reconstruct its 3D digital model, the structured-light measurement technology is used to establish a new 3D measurement system. Based on the Gray code and phase shifting coding algorithms, a new coding algorithm called Gray＋Phase shifting code is developed. Firstly, the map is divided into certain areas. Secondly, structured-light is projected separately in every area. Finally, every phase-shifting picture moves to right a certain pixel. The coding period is shortened due to the simplified plane projection, and the image processing is decreased. Moreover, the scanning rate is improved so that it is suitable to fast 3D model reconstruction. Some experiment results in our 3D surface information collection system are given to demonstrate the effectiveness of the presented scheme.