The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has become a crucial resource in astronomical research, offering a vast amount of spectral data for stars, galaxies, and quasars. This paper presents the data processing methods used by LAMOST, focusing on the classification and redshift measurement of large spectral data sets through template matching, as well as the creation of data products. Additionally, this paper details the construction of the Multiple Epoch Catalogs by integrating LAMOST spectral data with photometric data from Gaia and Pan-STARRS, and explains the creation of both low- and medium-resolution data products.