The invention provides height adjustment device for a concealed hinge. The height adjustment device comprises slopes arranged at the two ends of a frame leaf base and an adjustable mechanism vertically penetrating through door frame connection plates, wherein the tail end of the adjustable mechanism abuts against the slopes. In installation and use, after the concealed hinge is fixed to a door frame and a door leaf, if installation personnel find that the position of the door leaf is excessively high or low relative to the door frame, the position can be conveniently adjusted through the adjustable mechanism, the position of the concealed hinge in the height direction of the door frame can be adjusted, and therefore the door leaf can be driven to be adjusted relative to the door frame in height.