LAMOST first-tage regular survey has been successfully observed more than 150 000 galaxy spectra, which will provide necessary data for mining the precious and rare objects to improve the existing cosmogony theories. The advanced information technologies will provide effective tools to mine these rare samples from the vast amounts of spectral data. In this paper, the spectrum J152238.11+333136.1 is particularly chosen from LAMOST DR 5 by using the outlier mining method based on the DoPS method and intensively discussed the rare characteristics of P-Cygni profiles. Firstly, the basic information, the description of suspected P-Cygni profiles and the related data mining methods are introduced briefly. The P-Cygni shapes are shown in the wavelength of Hβ and ［OⅢ］λ4860, and inverted P-Cygni shapes are shown in the wavelength of NeⅢλ3869 and HeⅠλ5874. Secondly, the authenticity of the feature and its generation mechanism are discussed from the following four perspectives. (1) Homologous observation. The homologous observation of Sloan survey in 2004 (11 years before) did not present corresponding features on the spectrum, which might be due to ongoing evolutionary activities or fiber positioning errors; (2) By analyzing the spectral quality and reducing the residual of the skylight, it is analyzed whether the P-Cygni features are caused by observations or data processing. The inverted P-Cygni shapes in NeⅢλ3869 and HeⅠλ5874 have lower credibility. Meanwhile, by comparing the target spectrum with the super skylight, and the spectral characteristics of the spectrum observed by the adjacent fibers, the possibility that the P-Cygni profiles is caused by the sky background reduction process is illustrated; (3) Spectral sub-type differences. Near-infrared homologous observations such as IRAS and WISE showed that it is a Seyfert 2 galaxy. However, the emission line intensity ratio ［NⅡ］/Hα, ［OⅢ］/Hβ shows that it is HⅡ region. Considering the characteristics of optical and infrared photometry images, we infer that the two galaxies of the target may be on going the merging activities; (4) From the perspective of the physical mechanism that leads to the P-Cygni profiles, the possibility of the outflows triggered by galaxies, the outflows triggered by the ionized gas of star formation (star burst), and the super-wind by the Wolf-Rayet galaxies are carefully analyzed.