Laser powder bed fusion (L-PBF) is a promising technique for fabricating high-performance complex aluminum (Al) alloy components. However, conventional high-strength wrought Al alloys that are processed using L-PBF have limited application owing to their poor cracking resistance. To investigate the cracking mechanism, L-PBF was used to fabricate a 2024Al alloy. The resultant microstructure exhibited severe hot cracking, which occurred at grain boundaries with a high angle in both solidification and liquation cracks. Increasing the scanning speed increased the susceptibility to cracking. The effect of scanning speed on the eutectics content of Al2Cu and Al2CuMg and the residual stress in as-fabricated samples are discussed. Crack elimination at a low scanning speed could be ascribed to the lower thermal stresses and adequate liquid feeding during the late stage of solidification. In addition, based on the RDG (Rappaz-Drezet-Gremaud) model, a cracking susceptibility map was produced, in which the cracking susceptibility was determined to increase with an increase in the solidification rate, in agreement with experimental observation.