The scanning technology and diagnosis and treatment system of dental chairs play a better auxiliary role in the level of oral diagnosis and treatment as well as the doctor’s therapeutic effect. In this paper, we design an oral chairside scanning and diagnosis and treatment system, which includes two modules for scanning, acquiring, and managing oral image information. Taking CBCT as the main technology, the steps of image reconstruction, generation, estimation of tooth main axis, and reconstruction of independent tooth contour are carried out sequentially to obtain the three-dimensional network model of teeth. Through the dental clinic information management system, the case base is effectively managed to enhance operational efficiency. The system presented in this paper is tested and applied to analyze its effects during usage. The results show that the maximum difference between the measurement of this system and the manual measurement is not more than 1mm. The mean values of the errors of the system designed in this paper in the angular error and apical error are 3.547±1.556mm and 1.154±0.265mm, respectively. The P-value is less than or equal to 0.05, which is significant, and the system performs very well in these two aspects.