Avoiding cracking defects is crucial to ensuring processability in the laser powder bed fusion (LPBF) of metallic materials. In this study, a crack-free Ni-based superalloy with a high volume fraction of the γ′ phase was designed for the LPBF process using the thermodynamic approach. The results indicate that the designed SD01 Ni-based alloy was crack-free and over 21% of the spherical γ′ phase was uniformly distributed in the matrix after heat treatment. In addition, 1 wt.% TiB2 particles were introduced into the SD01 alloy to further enhance high-temperature mechanical performance. It was found that the morphology of the γ′ phase was altered from spherical to cubic structures, and its volume fraction increased from 21% to 40% after the TiB2 addition. The SD01-TiB2 composite exhibited an excellent combination of tensile strength (437.43 MPa) and elongation (7.71%) at 900 °C compared with the SD01 alloy (252.03 MPa, 3.02%). These findings provide a new metallic material design method for the LPBF of crack-free high-performance Ni-based materials.