The invention relates to a method for automatically fusing oral scanning tooth data and CBCT data. The method comprises the following steps: S1, loading oral scanning grid data; s2, dividing the mouth scanning grid data; s3, loading the CBCT data; s4, CBCT data AI segmentation is carried out; s5, carrying out gridding generation on a CBCT data segmentation result; s6, registration of oral scanning dental crown data and CBCT gridding data is carried out; s7, coordinate position information of the registered CBCT upper teeth and the registered CBCT lower teeth is calculated, and new CBCT upper tooth and lower tooth grid data are generated; s8, matching the upper tooth crown with an association point set; s9, matching a lower tooth crown with an association point set; s10, carrying out CBCT grid data deformation; and S11, reconstruction optimization of the CBCT grid data is carried out. According to the automatic fusion method based on the oral scanning tooth data and the CBCT data, the advantages of high dental crown precision of the oral scanning data and complete tooth root form of the CBCT data can be integrated, the appearance form after the oral scanning dental crown and the CBCT teeth are integrally fused is obtained, clinical doctors can be well guided to carry out work, and the tooth treatment precision is improved.