Stellar occultation technology measures the transmission spectra of light of stars through the atmosphere modified by extinction and refraction and obtain various atmospheric density information by using the absorption differences among components of different wavelengths. While the LEO(Low Earth Orbit) satellite and the star are located on both sides of the earth, the low-orbit satellite receives the transmission spectra at different tangent heights, which constitutes a stellar occultation technology observation. The observed height of the transmission spectra can range from the stratosphere to the low thermosphere, and different bands can be used for the inversion of the density of different atmospheric trace components. Stellar occultation technology has the advantages of multiple detection parameters, global coverage, high vertical resolution, and self-calibration. The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument onboard the European Space Agency’s ENVISAT satellite measures transmission spectra by stellar occultation technology to detect stratospheric ozone trends. GOMOS is precisely designed and high resolution, operating stably for a decade(2002—2012). With the detection wavelength spanning from ultraviolet to visible light, the spectral inversion and vertical inversion method is used to calculate the atmospheric composition density. GOMOS data provides reliable data support for long-term monitoring of changes from the stratosphere to the lower thermosphere. Using the dataset of GOMOS, this paper proposes a simple inversion method the onion-peeling method to retrieve the ozone density in the near-space region. Under the assumption of symmetrical and layered horizontally atmosphere, the onion-peeling method uses a single band spectrum to inversion, assuming that the atmospheric absorption effect of the spectra at this wavelength is entirely caused by ozone, which means the wavelength at which ozone absorption is chosen to occupy absolute advantage. After analysis and comparison, it is suitable to use the spectra of 290 nm to retrieve the density at the altitude during 50~100 km and the spectral of 600 nm to retrieve the density at the altitude during 15~50 km. According to Beer-Lambert’s law, ozone density is obtained by the onion-peeling method using the stellar transmission spectra from top to bottom at the tangent height. The results of this onion-peeling method are consistent with the results official released results of GOMOS.