  We study the effect of hydrostatic pressure on the magnetotransport
properties of the zirconium pentatelluride. The magnitude of resistivity
anomaly gets enhanced with increasing pressure, but the transition temperature
$T^{\ast}$ is almost independent of it. In the case of H $\parallel$ $b$, the
quasi-linear magnetoresistance decreases drastically from 3300$\%$ (9 T) at
ambient pressure to 400$\%$ (14 T) at 2.5 GPa. Besides, the change of the
quantum oscillation phase from topological nontrivial to trivial is revealed
around 2 GPa. Both demonstrate that the pressure breaks the accidental Dirac
node in ZrTe$_{5}$. For H $\parallel$ $c$, in contrast, subtle changes can be
seen in the magnetoresistance and quantum oscillations. In the presence of
pressure, ZrTe$_{5}$ evolves from a highly anisotropic to a nearly isotropic
electronic system, which accompanies with the disruption of the accidental
Dirac semimetal state. It supports the assumption that ZrTe$_{5}$ is a semi-3D
Dirac system with linear dispersion along two directions and a quadratic one
along the third.
