  We identify 20 F-type Herbig stars and provide a list of 22 pre-main-sequence
candidates from LAMOST DR8. The effective temperature, distance, extinction,
stellar luminosity, mass, and radius are derived for each Herbig star based on
optical spectra, photometry, Gaia EDR3 parallaxes, and pre-main-sequence
evolutionary tracks. According to spectral energy distributions, 19 F-type
Herbig stars belong to Class II YSOs, and one belongs to the flat-spectrum
class. Four have Spitzer IRS spectra, of which three show extremely weak
polycyclic aromatic hydrocarbons emissions, and three with both amorphous and
crystalline silicate emissions share the similar parameters and are at the same
evolutionary stage. We detect a solar-nearby outbursting EXor Herbig star
J034344.48+314309.3, possible precursor of a Herbig Ae star. Intense emission
lines of HI, HeI, OI, NaI, and CaII originated from the rapid accretion during
the outbursts are detected in its optical spectra, and silicate emission
features are detected in its infrared spectrum. We also make a statistic
analysis on the disk properties of all known Herbig stars using the defined
infrared spectral indices. The proportion of Herbig stars with moderate
infrared excesses decreases as effective temperature increases. The majority of
the precursors (F-, G-, or K- type) have moderate infrared excesses. Hotter
Herbig stars tend to have a larger proportion with large infrared excesses. The
trends may be due to the fact that hotter stars have larger areas of
re-emitting dust, although there is some scatter due to the particularities of
each disk.
