An augmented-reality question-answering system based on a 3D-scan module includes a mobile device and a server. The mobile device includes a video capture module, a 3D-scan module, an augmented-reality display module, a voice interactivity module, and a web service module. The server includes a 3D-scan model analysis module, a 3D-scan model storage module, an interactive video storage module, a question-answering system, and a web service module. For the design of the proposed augmented-reality question-answering system based on a 3D-scan module, a user can use the mobile device with a 3D-scan module to perform the processes of 360-degree surround shooting and transmit these pictures to the server with a 3D-scan model analysis module, and the 3D-scan model analysis module can analyze these pictures and generate 3D model for the augmented-reality display module.