A chassis device and its cover structure and lifting mechanism, the chassis structure includes a chassis, a cover and a lifting mechanism further including a first magnetic member fixed to the cover, a second magnetic member fixed to the chassis; a movable sleeve sheathed on the second magnetic member and capable of sliding with respect to the second magnetic member, an elastic element installed between the chassis and the movable sleeve and pushing the movable sleeve away from the chassis to resume its original position, and a third magnetic member fixed to the movable sleeve, and the third magnetic member has a side attracted or repelled with respect to the first magnetic member and the other side attracted or repelled with respect to the second magnetic member. The second and third magnetic members have a magnetic attraction force greater than an elastic restoring force of the elastic element.