A method of three-dimensional printing of the disclosure is used to form a three-dimensional object stacked by a plurality of layers of object unit. The method of three-dimensional printing includes: forming and curing a layer of uncolored body; forming a color layer at the contour of the layer of uncolored body so that the layer of uncolored body and the color layer form a layer of object unit; and forming a cover layer at the contour of the layer of object unit so that the color layer is located between the layer of uncolored body and the cover layer.