  M-type stars are crucial for stellar activity studies since they cover two
types of magnetic dynamos and particularly intriguing for habitability studies
due to their abundance and long lifespans during the main-sequence stage. In
this paper, we used the LAMOST DR9 catalog and the GALEX UV archive data to
investigate the chromospheric and UV activities of M-type stars. All the
chromospheric and UV activity indices clearly show the saturated and
unsaturated regimes and the well-known activity-rotation relation, consistent
with previous studies. Both the FUV and NUV activity indices exhibit a
single-peaked distribution, while the {\rm H$\alpha$} and \rm {Ca
\scriptsize{\uppercase\expandafter{\romannumeral2}} \normalsize H$\&$K} indices
show a distinct double-peaked distribution. The gap between these peaks
suggests a rapid transition from a saturated population to an unsaturated one.
The smoothly varying distributions of different subtypes suggest a
rotation-dependent dynamo for both early-type (partly convective) to late-type
(fully convective) M stars. We identified a group of stars with high UV
activity above the saturation regime (log$R^{\prime}_{\rm NUV} > -2.5$) but low
chromospheric activity, and the underlying reason is unknown. By calculating
the continuously habitable zone and the UV habitable zone for each star, we
found about 70\% stars in the total sample and 40\% stars within 100 pc are
located in the overlapping region of these two habitable zones, indicating a
number of M stars are potentially habitable. Finally, we examined the
possibility of UV activity studies of M stars using the China Space Station
Telescope.
