An assembling component includes a frame and a cover. The frame has an opening, a first plane, and a first assembling structure. The first plane surrounds and is adjacent to the opening. An area of the opening is larger than an area of the first plane. The first assembling structure is formed on the first plane. The cover covers the opening and the first plane and has a second assembling structure. A side of the cover has a second plane parallel to the first plane. The second assembling structure is formed on the second plane. An end of the second assembling structure extends from the second plane toward another side of the cover. The second assembling structure is assembled with the first assembling structure to stop the cover from moving relative to the frame.