The invention provides a monitoring camera device, comprising a monitoring camera and an LED light supplement lamp which is arranged in the same direction as the monitoring camera, wherein the LED light supplement lamp comprises a shell, and a circuit control module and an LED lamp that are arranged inside the shell; a reflection cup and a light transmitting window are arranged at the front end of the shell, the circuit control module is connected with the LED lamp, the light transmitting window is matched with the outlet of the reflection cup, the light transmitting window is provided with a convex lens, and the power of the LED lamp is 5-50W. The invention also provides an application method of the monitoring camera device. According to the monitoring camera device provided by the invention, the phenomenon that the headlamp of the vehicle directly illuminates the monitoring camera can be avoided, and the tailing phenomenon in the camera shooting process can be completely avoided; the adopted light supplement lamp has low power and is energy-saving and environmentally friendly; the light emitted by the light supplement lamp is uniform and soft, the sight line of the driver cannot be affected, safe driving of the driver can be guaranteed, and high security can be achieved; and the identification rate of vehicle registration plates can be increased, and the requirements of the intelligent license plate retrieval for the image clarity can be met.