A three-dimensional head portrait generating method executes on an electronic device. The three-dimensional head portrait generating method establishes a three-dimensional head portrait model with a plurality of feature points according to front face information, wherein feature points form a plurality of first grids on the three-dimensional head portrait model; maps a first part of the feature points of the three-dimensional head portrait model to a left face image to form a plurality of second grids on the left face image; maps a second part of the feature points of the three-dimensional head portrait model to a right face image to form a plurality of third grids on the right face image; and superimposes the left face image and the right face image onto the three-dimensional head portrait model according to a correspondence among the first grids, the second grids and the third grids, to generate a three-dimensional head portrait.