A method of constructing tooth images utilizes a probe to take images of teeth at one place using a first light ray of wavelength less than or equal to 460 nm and a second light ray of wavelength greater than or equal to 600 nm, thereby generating a first image and a second image. After receiving the first image and the second image, an image processing unit superimposes the first image and the second image to produce a composite tooth image. Using the light of wavelength less than or equal to 460 nm has the advantage of reducing reflection disturbance from saliva, thereby increasing the precision in tooth images.