A flashlight lamp circuit with automatic light adjustment includes a flashlight charging unit for controlling charging of a main capacitor, a flashlight activation unit activating the flashlight lamp to project a flashlight on the photographed object according to a flashlight control signal, a light sensor receiving and converting a light from the photographed object into an electric signal, an integral circuit receiving the electric signal and having an adjustable circuit resistance. When the amount of flashlight reaches a required light exposure, the flashlight control unit extinguishes the flashlight lamp.