The optical spectrometer, an instrument used to detect and analyze spectra with various wavelength components of incident light, has a growing demand for applications in fundamental research, industrial production and daily life. Conventional spectrometers based on precise optical dispersion components usually necessitate large volume and weight, which hardly meet the trend of miniaturization and low cost for diverse applications. We realize a filter-array-based computational reconstructive optical spectrometer through combining a series Cs_0.1MA_0.9PbX₃ (X is Cl, Br, I) perovskite materials with different visible light absorption characteristics prepared by spin coating method and complementary metal oxide semiconductor sensor. Considering the spectral response of the perovskite film array, the non-negative Tikhonov regularization method is used to reconstruct the spectra. Finally, the designed optical spectrometer is tested and verified, which exhibits a spectral resolution of 27 nm at 500 nm wavelength and achieves a certain spectral resolution within the visible range.