A cover module of an electronic device and a control method thereof are provided. The cover module includes a body, a flexible connecting element, and a flip cover. The body has an opening exposing the connector. A sidewall of the opening has a first fixing structure. The flip cover is in the opening, and a sidewall of the flip cover has a second fixing structure locked with the first fixing structure. The flexible connecting element is connected between the body and the flip cover. When a force is applied to the flip cover, the flexible connecting element is deformed, the flip cover moves with the deformation of the flexible connecting element, and the locking between the first and the second fixing structures is released to cause the flip cover swinging open away from the body with a part of the flexible connecting element as an axis.