The present invention provides a solid pharmaceutical formulation of PARP inhibitors and its use thereof, and more specifically a solid dispersion powder including 5-fluoro-1-(4-fluoro-3-(4-(pyrimidin-2-yl)piperazine-1-carbonyl)benzyl)quinazoline-2,4(1H,3H)-dione and polymers, wherein the content of polymers is from about 50 wt % to about 80 wt %, and wherein less than 10 wt % of 5-fluoro-1-(4-fluoro-3-(4-(pyrimidin-2-yl)piperazine-1-carbonyl)benzyl)quinazoline-2,4(1H,3H)-dione is in crystalline form. The present invention also provides a method for preparing the solid dispersion powder, a pharmaceutical composition including the solid dispersion powder and the use of the pharmaceutical composition for treating diseases caused by PARP activity abnormalities.