<p>The rapid development of the space field has presented elevated requirements for the performance of lightweight structures under high-temperature conditions, while the additive manufacturing of aluminum alloy for aerospace is faced with the problem of insufficient high temperature performance and cracking. To this end, we designed a novel Ti– and Ag-modified Al–Cu–Mg alloy using laser powder bed fusion, which showed a high mechanical performance with a tensile strength of 426&#xa0;MPa at room temperature and 314&#xa0;MPa at 200&#xa0;°C, greatly surpassing the majority of currently developed heat-resistant Al alloys. The microstructural observation demonstrated that Ti element facilitates the formation of coherent L1₂–Al₃Ti particles, thereby contributing to grain refinement, while Ag segregates to the grain boundaries and forms small Ag₂Al particles, which effectively enhance pinning effects. Additionally, Ag₂Al particles at high temperature significantly contribute to the superior performance in elevated temperature conditions of the designed alloy. Thus, this study has developed a novel alloy with Ag and Ti elements addition and clarified the crucial role of Ag and Ti elements in modifying additively manufactured Al alloy, laying a foundation for the application of lightweight heat-resistant components in the future.</p> Graphical Abstract <p></p>