Heavy oil hydrotreating catalyst and application thereof

The invention relates to a heavy oil hydrotreating catalyst and application thereof. The catalyst comprises an alumina carrier, at least one of group VIII metal components and at least one of group VIB metal components, and is characterized in that: the alumina carrier is alumina obtained by forming and roasting pseudo-boehmite of which n is more than or equal to 1.1 and less than or equal to 2.5, wherein n=D(031)/D(120), D(031) represents the crystal grain size of a crystal surface represented by a (031) peak in an X-ray diffraction (XRD) spectrogram of pseudo-boehmite crystal grains, and D(120) represents the crystal grain size of a crystal surface where a (120) peak in the XRD spectrogram of the pseudo-boehmite crystal grains is positioned; and D=K lambda/(B cos theta), lambda is the diffraction wavelength of a target material, B is the corrected half-peak width of a diffraction peak, and 2theta is the position of the diffraction peak. Compared with the prior art, the catalyst has higher performance of rem