The invention relates to a color jet printer and a jet printing method thereof. The color jet printer comprises a machine frame, an upright post, a horizontal beam, a jet printing worktable and an electric cabinet, wherein the structure of the jet printing worktable comprises a parallelly traveling worktable and a rotary conveyer belt; textile to be printed is tiled on the parallelly traveling worktable or the rotary conveyer belt; and pattern areas of the textile are sprayed with white bottom layers by a computer programmed NO. 1 inking box and white bottom areas are sprayed with colored patterns by a computer programmed NO. 2 inking box. By utilization of the prior computer programmed color jet printing technology to perform jet printing of patterns on the textile such as T-shirts and so on or planar carriers, the jet printing method improves the work efficiency, reduces the cost and strengthens the viewing effect compared with the prior printing method. The white bottom layers are printed on the pattern areas of the textile at first and then sprayed with patterns, thereby the jet printing method can improve the adhesion force of the patterns and the textile, guarantee that the patterns are not fallen off and strengthen the jet printing effect of the patterns. Moreover, the white bottom layers of the textile can be respectively printed by the jet printing technique, the hot transfer printing technique or the silk-screen printing technique.