A printing method for a three-dimensional object and system thereof, the method includes: analyze and build a three-dimensional model of a work piece to be printed. Discrete three-dimensional model along the first axis into the two-dimensional multi-level, and get a second two-dimensional plane coordinate for the second axis and the third axis from each layer in two-dimensional layer. Each time will according to the second two-dimensional horizontal coordinate for the second axis and the third axis sequentially for a second two-dimensional coordinates of each layer of the work piece axis line by line dot matrix printing. The present invention can overcome the limitations of existing 3D printing printer, and to achieve a three-dimensional model of the single direction infinite print. Even smaller three-dimensional printer does not require changes to existing structures.