1. A three-dimensional printing method, adapted for printing a three-dimensional object, the three-dimensional printing method comprising: obtaining a plurality of layer objects of a three-dimensional model and generating a plurality of two-dimensional images, corresponding to a slice plane, of each of the layer objects, wherein the layer objects comprise a first layer object and a second layer object adjacent to each other; stacking the first layer object and the second layer object to generate thickness stack information of a stack object when a comparison relationship between the two-dimensional image of the first layer object and the two-dimensional image of the second layer object matches a stack condition; and initiating a printing mechanism according to the thickness stack information to print the three-dimensional object associated with the three-dimensional model.