  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 amount of spectra. In this work, we build a new
carbon star catalog based on the 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 sub-classified due to their low signal-to-noise.
Moreover, by comparing with LAMOST DR7 pipeline we find 567 more carbon stars
and visually sub-classify them. We find that on the $J-H$ vs. $H-K_{\rm s}$
two-color diagram, C--N stars can be reliably distinguished from the other
three sub-types. 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_{\rm G}>$5.0\,mag. 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 dC stars distribute at high Galactic latitudes.
