The invention belongs to the field of carton packaging machines. The aim is that a star wheel system carton taking mechanism can reduce the speed and the accelerated speed of a carton taking point and a carton placing point, and therefore the mechanism running reliability is improved. According to the technical scheme, an ellipse-round gear combination planetary gear train carton suction mechanism comprises a rotating shaft rotationally positioned on a fixed support, the left side of the rotating shaft is driven by a power mechanism, a sun gear coaxial with the rotating shaft is fixed to the right end of the fixed support, the right end of the rotating shaft penetrates a hole in the center of the sun gear to be fixedly provided with a rotating disc serving as a planet wheel support, and at least one pair of transmission short shaft and transmission long shaft parallel to the axis of the rotating disc are rotationally positioned on the rotating disc; the transmission short shaft is fixedly provided with an ellipse middle wheel and a round middle wheel meshed with the sun gear, one end of the transmission long shaft is fixedly provided with an ellipse planet wheel meshed with the ellipse middle wheel, and the other end of the transmission long shaft is fixedly provided with a suction disc used for sucking cartons through a suction disc support.