  We investigate the stationary, spherically symmetric accretion of a
degenerate relativistic Fermi gas onto a Reissner-Nordstr\"{o}m black hole. The
accretion theory is based on the Boyer-Lindquist coordinates and the Fermi gas
follows Fermi-Dirac statistics at infinity. We have derived the expression for
the particle current density, the stress energy-momentum tensor, and three
accretion rates. As the charged particle falls into the black hole, both the
mass and the charge of the black hole increase. Consequently, the mass
accretion rate and charge accretion rate are proportional to the particle
accretion rate. We have also provided analytical results at infinity and
numerical results within a finite range for these quantities. Our results
indicate that the accretion rate decreases as the charge of the black hole
increases, suggests that the presence of naked singularities is avoided in
black hole accretion theory. In this paper, we also discovered that the
accretion model of Vlasov gas behaves as an anisotropic fluid containing two
perfect-fluid components. One component represents the isotropic fluid of Fermi
gas, while the other represents a null fluid. When using the Boyer-Lindquist
coordinate system, we observed that the contribution from the null fluid
persists even at infinity, which led to the radial pressure always smaller than
the tangential pressure. Therefore, it's not appropriate to treat the accretion
model as a perfect fluid at infinity.
