The present invention relates to medical devices and provides an intra-oral scanner for a digital impression. The intra-oral scanner has a window for limiting an acquisition range. The intra-oral scanner sequentially includes, along a light path, a three-color LED light source module, a microlens array sheet, a collimator lens group, a gray coding grating plate, an optical deflector, a projection lens group, a first reflector, a second reflector and a third reflector positioned in parallel with each other with their reflective surfaces opposing to each other, and a camera. The intra-oral scanner can perform a scan directly in the human oral cavity and obtain the digital impression of three-dimensional topography of the tooth and soft tissue in real-time, thereby meeting the requirements of dentists and dental technicians to quickly and accurately obtain the oral impressions.
