The invention relates to the field of building door and window accessories, and particularly discloses a quick mounting structure for a hidden hinge. The quick mounting structure comprises a fixed bottom plate which is in a right-angled bending shape, and is characterized in that a vertical rotating baffle plate is riveted on a vertical surface of the fixed bottom plate; two round stepped holes are formed in a horizontal plane of the fixed plate; and mounting screws with hexagonal holes are riveted together with horizontal rotating baffle plates . The quick mounting structure has a simple structure, is easy and convenient to mount, and cannot damage profiles; moreover, a conception of a mounting structure that the profiles are clamped by the rotating baffle plates and the hinge is provided, so that quick mounting of the hidden hinge is realized, and the structure is suitable for being widely popularized and used.