MoAlB MAB phase thin films have garnered ever-increasing attention due to their fascinating properties and extensive range of functional applications. Reducing the synthesis temperature of MoAlB thin films is crucial for discerning their limitations and exploring potential applications. In the present study, a strategy was employed to lower the synthesis temperature of the MoAlB thin film by designing (Mo–B)/Al nanostructured multilayers (NMs), which induce the formation of intermetallic compounds as transitional species. The results demonstrated that the synthesis temperature of MoAlB thin films was reduced within the temperature range of 773 K–873 K. The reaction proceeded as expected in two steps: initially, the formation of Al12Mo intermetallic compounds took place at the NMs' interface, followed by the subsequent reaction between Al12Mo and MoBx, resulting in the formation of the MoAlB MAB phase. Additionally, the MoAlB thin film exhibited a hardness of 16 ± 0.8 GPa and an elastic modulus of 363 ± 13 GPa. Importantly, this work provides valuable insights into achieving the synthesis of MAB phase materials at lower temperatures.