  The black hole candidate MAXI J1348-630 was discovered on January 26th, 2019,
with the Gas Slit Camera (GSC) on-board \textit{MAXI}. We report a detailed
spectral analysis of this source by using the archived data of \textit{NuSTAR}.
A total of 9 observations covered the complete outburst evolution of MAXI
J1348-630 from the hard state to the soft state and finally back to the hard
state. Additionally, the intermediate state is found in the transition from the
hard state to the soft state. We use the state-of-art reflection model
\verb'relxill' family to fit all the 9 spectra, and the spectra from two focal
plane module detectors of \textit{NuSTAR} are jointly fitted for each
observation. In particular, we concentrate on the results of the black hole
spin parameter and the inclination of the accretion disk. Based on the analysis
of the inner radius of the accretion disk, we obtain the spin parameter $a_*
=0.78_{-0.04}^{+0.04}$, and the inclination angle of the inner disk $i =
29.2_{-0.5}^{+0.3}$ degrees. Furthermore, we also find that when the black hole
is in the hard state, the accretion disk would show a significant truncation.
The high iron abundance and ionization of the accretion disk obtained in the
fitting results can be possibly explained by the high density of the accretion
disk.
