Three-dimensional printing method

A three-dimensional printing method adapted for a three-dimensional printer, which comprises a model printing head, a color printing head, and a platform, wherein the model printing head is configured to print at least one forming layer on an X-Y plane of the platform with a forming material, the model printing head and the color printing head are arranged along an X-axis and co-constructed, a space exists between the model printing head and the color printing head along the X-axis, and the color printing head is configured to color a coloring zone of the forming layer along a Y-axis, the three-dimensional printing method comprising:

• providing information of the coloring zone of the forming layer;
• determining a coloring path of the color printing head along the Y-axis according to the information of the coloring zone by a processor, wherein the coloring path forms a single coloring;
• determining the number of the colorings {Bn} of the color printing head according to the information of the coloring zone by the processor, wherein n is a positive integer;
• determining whether an orthogonal projection size of the coloring zone on the X-axis is smaller than the space by the processor;
• and
• if the orthogonal projection size of the coloring zone on the X-axis is smaller than the space, not driving the model printing head to perform printing by the processor when the color printing head colors the coloring zone.