Al flake was used as the filler to optimize the properties of vinyl-polysilazane based photo-curable resin derived ceramics (P-PDCs) manufactured by digital light processing. Al flake addition showed a significant inhibitory effect on the macroscopic cracking and the micrometer voids of the P-PDCs. With the Al flake content of 0.6 wt%, P-PDCs pyrolysed at 1300 °C exhibited a maximum Vickers hardness and bending strength of 9.47 GPa and 89.39 MPa, respectively. The Nano-indentation measurements showed an improvement of the elastic modulus from 74.56 GPa to 85.62 GPa, and the indentation hardness from 7.12 GPa to 12.47 GPa as the increase of the Al flake. During pyrolyzing, the pristine Al flake reacted with the pyrolysed by-product obtained hollow lamellar Al2O3 phase of varying aspect ratios in the forming matrix, which acted not only as a strengthening phase on the mechanical properties but also as a channel for the release of gaseous.