A conducting hinge device is adapted to be mounted to an electric toy gun that includes a first body-section, a second body-section pivotally connected to the first body-section, an electric motor unit, and a battery unit. The conducting hinge device includes a conducting unit and a hinge conductor unit. The conducting unit is installed between the first body-section and the second body-section, and includes two pin members for being electrically connected to the electric motor unit. The hinge conductor unit includes two hinge leaves that are mounted co-movably to the second body-section, and that are each sleeved on a respective one of the pin members and electrically connected to the battery.