  We systematically investigate the influence of high pressure on the
electronic transport properties of layered ferromagnetic materials, in
particular, those of Fe$_3$GeTe$_2$. Its crystal sustains a hexagonal phase
under high pressures up to 25.9 GPa, while the Curie temperature decreases
monotonously with the increasing pressure. By applying appropriate pressures,
the experimentally measured anomalous Hall conductivity, $\sigma_{xy}^A$, can
be efficiently controlled. Our theoretical study reveals that this finding can
be attributed to the shift of the spin--orbit-coupling-induced splitting bands
of Fe atoms. With loading compression, $\sigma_{xy}^A$ reaches its maximal
value when the Fermi level lies inside the splitting bands and then attenuates
when the splitting bands float above the Fermi level. Further compression leads
to a prominent suppression of the magnetic moment, which is another physical
cause of the decrease in $\sigma_{xy}^A$ at high pressure. These results
indicate that the application of pressure is an effective approach in
controlling the anomalous Hall conductivity of layered magnetic materials,
which elucidates the physical mechanism of the large intrinsic anomalous Hall
effect.
