The paper presents a method with the technique of combination filtering of spectrum and the technique of DSP control for the simulation and recognition of the spontaneously lightening object and stellar map in the universe. The magnitude and the spectrum of a star can be simulated in a wide dynamic range. We established the mathematical models of the Vega's visible light spectrum and luminous flux density. Tungsten-halogen lamp as a light source is used to fit the linear light of the spontaneously lightening object in the universe. Through the experiment, it shows that the more sub-channels there are while filtering spectrum in the visible spectrum, and the more degrees the variable neutral density filters and the narrow-band attenuators have, more close to the actual spectrum the simulated spectrum is. It is proved that using the PID technique is beneficial to the output of the accurate and steady radiation from the light sources. The experiment shows that the using of this method can get perfect result in fitting and simulating the spectrum, magnitude and the stellar map of the spontaneously lightening object . The analysis of the consistent result and the experimental error is also discussed in detail in this paper.