Carbon stars are excellent kinematic tracers of galaxies and play important roles in understanding the evolution of the Galaxy. Therefore, it is worthwhile to search for them in a large number of spectra. In this work, we build a new carbon star catalog based on the Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST) DR7 spectra. The catalog contains 4542 spectra of 3546 carbon stars, identified through line index and near-infrared color-color diagrams. Through visual inspection of the spectra, we further subclassify them into 925 C-H, 384 C-R, 608 C-N, and 1292 Ba stars. However, 437 stars could not be subclassified due to their low signal-to-noise. Moreover, by comparing with the LAMOST DR7 pipeline we find 567 more carbon stars and visually subclassify them. We find that on the J-H versus H-Ks two-color diagram, C-N stars can be reliably distinguished from the other three subtypes. Additionally, by utilizing the Gaia distance, we study the distribution of carbon stars in the H-R diagram and identify 258 dwarf carbon stars by the criterion M_G_>5.0mag. Finally, we present the spatial distribution in Galactic coordinates of the 3546 carbon stars. The majority of C-N, C-R, and Ba stars are distributed at low Galactic latitudes, while most C-H and dwarf carbon stars are distributed at high Galactic latitudes.