The invention discloses a vertical self-stabilization control device and a vertical self-stabilization control method for a sliding staff/prism bar. A third-stage movable arm in the device is connected with a clamp by a changeover mechanism; a second-stage movable arm is connected with the third-stage movable arm through one X-axis rotational joint; an X-axis servo motor is arranged in the X-axisrotational joint; a first-stage movable arm is connected with the second-stage movable arm through a Z-axis rotational joint; a Z-axis servo motor is arranged in the Z-axis rotational joint; a holdingrod is held with hands to be connected with the first-stage movable arm through the other X-axis rotational joint; a sensor is arranged on the clamp. The method comprises the following steps: S1, sampling attitude dip angles thetax(i) and thetaz(i) at T(i); S2, calculating attitude deviation Ex(i) and Ez(i); S3, carrying out PDI calculation to obtain compensation angle signals Ox(i) and Oz(i); S4, executing compensation action by the X-axis servo motor and the Z-axis servo motor. The vertical self-stabilization control device and the vertical self-stabilization control method, disclosed by the invention, have the advantages of simple and reliable structure, high response speed, high execution efficiency, high degree of automation and capability of reducing labor intensity of manually supporting the staff.