A camera module with a hinge mechanism is installed on an electronic device. The camera module housing has two hollow cylinder-shaped shafts at two opposite ends. Two hollow cylinder-shaped shafts are pivotally connected with the electronic device. A camera is disposed in the housing. A hinge portion is configured inside at least one of the two hollow cylinder-shaped shafts. Two ends of the hinge portion are first and second brackets, which are respectively secured to ground terminals of the camera module and the electronic device. A first cam is secured to the first bracket. A connection shaft, of which one end is secured to the second bracket, goes through a spring, through holes of a second cam, the first cam and the first bracket. When the housing rotates, interactions among the spring, the first cam and the second cam provide regional positioning and regional automatic rotation functionalities.