The invention discloses a ladle capping and uncapping device. The ladle capping and uncapping device comprises a rack base, a first driving rod piece, a second driving rod piece, a first pin gear ringarranged on the first driving rod piece, a second pin gear ring arranged on the second driving rod piece, a first main drive gear meshed with the first pin gear ring, a second main drive gear meshedwith the second pin gear ring, a main transmission shaft connected to the first main drive gear and the second main drive gear, and a driving mechanism which provides a driving force for the main transmission shaft to rotate, wherein the first driving rod piece and the second driving rod piece are rotationally arranged on the rack base, are parallel to each other, and are in rotational connectionwith a ladle cap. The ladle capping and uncapping device adopts a dual-rocker mechanism to ensure that the ladle cap is fastened and pressed above the edge of a ladle during capping and the ladle capcan be placed above at a certain tilt angle during uncapping, so that the ladle capping and uncapping device is prevented from being damaged by splashed molten iron during iron discharge. Meanwhile, the ladle capping and uncapping device has the advantages of small occupied area and high running stability.