The invention discloses a paper jamming preventive robot at a paper outlet of a vertical printer, mainly relates to transmission of feedback control and mechanical portions of motors by the aid of sensors and is also applied to diversified similar places. The paper jamming preventive robot mainly comprises a motor, a worm and gear transmission actuator, a flexible rope, pulleys, hole alignment sensors, a controller, a paper blocking frame, a paper carrying table, a limit switch, upright columns and the like. The pulleys are mounted on the tops of the upright columns, so that the paper carrying table can ascend and descend under the control of the flexible rope under the guidance effects of the pulleys. The paper jamming preventive robot has the advantages that the motor can rotate clockwise and anticlockwise under the control of the hole alignment sensors and the controller, so that ascending and descending of the paper carrying table can be adjusted, printed paper sheets can be timely shifted from the outlet of the printer, and the problem of paper jamming due to excessively high quantities of paper sheets at an outlet of an existing printer when the existing printer independently works for a long time can be solved.