An image processing method and an image processing device includes: receiving image data of a user transmitted by an endoscope, storing and splicing to obtain spliced image data; determining the block corresponding to the spliced image data, determine the position of the block in the stored three-dimensional image contour of the user, reconstructing the spliced image data at the corresponding determined position in the three-dimensional image contour of the user to obtain reconstructed three-dimensional image data and update the currently stored three-dimensional image model of the user, according to the stored three-dimensional image frame database; and displaying the updated three-dimensional image model of the user. The three-dimensional image of the oral cavity can be reconstructed without continuous and orderly scanning of the oral cavity, the dynamic display can be performed, the user interaction effect can be improved, and the self-service three-dimensional true color model selection can be supported.