A 3D facial reconstruction system includes a main color range camera, a plurality of auxiliary color cameras, a processor and a memory. The main color range camera is arranged at a front angle of a reference user to capture a main color image and a main depth map of the reference user. The plurality of auxiliary color cameras are arranged at a plurality of side angles of the reference user to capture a plurality of auxiliary color images of the reference user. The processor executes instructions stored in the memory to generate a 3D front angle image according to the main color image and the main depth map, generate 3D side angle images according to the 3D front angle image and the plurality of auxiliary color images, and train an artificial neural network model according to a training image, the 3D front angle image and 3D side angle images.