Platinum diselenide (PtSe2) is a newly discovered 2D transition metal dichalcogenide, and is further theoretically identified as a candidate of type-II Dirac semimetals. The electrical transport study of PtSe2 microflakes may provide great potential not only in fundamental physics, but also for future electronic applications. We report the anomalous magnetotransport properties of PtSe2 microflakes. The anisotropic magnetoresistance of PtSe2 microflakes can be normalized by introducing a 3D scaling factor [Formula: see text], where θ is the magnetic field angle with respect to the c axis of the crystal and γ is the mass anisotropic constant of electrons. Additionally, the non-monotonic temperature-dependent magnetoresistance of PtSe2 microflakes is observed both in the perpendicular and in-plane magnetic field orientations. This anomalous magnetotransport behaviour may be ascribed to the novel features of type-II Dirac fermions; however, the exact physical mechanism deserves further investigation.