The invention discloses a low-temperature-doped luminescent aluminum nitride thin film and a preparation method thereof. The method comprises the following steps: preparing a mosaic target, and placing the mosaic target on a magnetic filtration electric-arc-plating target; chemically cleaning the surface of a matrix; placing the matrix into an electric-arc ion plating machine, and vacuumizing until the background vacuum degree is less than 3.0*10-3Pa; adding bias voltage of -800V; starting a curved arc magnetic filter and the magnetic filtration electric-arc-plating target to perform argon arc plasma bombardment cleaning on the matrix; maintaining current of a magnetic filtration tube, current of the electric-arc target and duty cycle, regulating and controlling the bias voltage to -100 to -400V, introducing nitrogen, and film-coating for 30-90 minutes; and switching off the magnetic filtration electric-arc-plating target and the curved arc magnetic filter, and then taking out a sample to obtain the doped luminescent aluminum nitride thin film. During the preparation process, the temperature of the sample is not more than 180 DEG C, and diffusion heat treatment is not required after deposition. The invention has simple preparation process and easy operation, and electrical and mechanical automatic control can be used in the film-coating course.