The invention relates to the technical field of teaching systems, and, more specifically, relates to an AR (augmented reality) CAD teaching method and system. The teaching method mainly comprises thesteps: building a three-dimensional model through 3D software, importing a stereoscopic model, a model graph and three views into three-dimensional animation software, carrying out the collection of two-dimensional images in a classroom through a camera, carrying out the recognition through the three-dimensional animation software, exporting a three-dimensional stereoscopic model file, and displaying the three-dimensional stereoscopic model file, wherein the display mode can be changed so as to observe the three-dimensional stereoscopic model at multiple angles. The teaching system comprises aplatform main body, and a computer and a display mounted on the platform main body. The platform main body is provided with a camera, a gesture sensor and a projector, wherein the camera, the gesturesensor and the projector are electrically connected with the computer. The method and system employ the AR mode, also can achieve the real-time interaction through gestures, achieve the conversion between the two-dimensional images of the classroom and the three-dimensional mode, bring convenience to students for quickly building a three-dimensional model stereo architecture, and help students create 3D thinking.