The microstructure and mechanical properties of 2524 Al alloy after quenching in liquid nitrogen (LN₂) were investigated by TEM and compared with those of cold water quenching. The results show that the LN₂ quenching process effectively induces the formation of dislocation loops. These loops become large and unevenly distribute after aging for 15 min. Furthermore, such loops become rapidly immobilized by the precipitation of coarse S phases after 1 h aging. The alloy quenched in LN₂ demonstrates superior peak hardness and displays a more rapid response to subsequent aging treatments compared with the cold water-quenched one. Despite the short aging time, LN₂-quenched sample achieves tensile strength of 488 MPa. This enhanced strength is attributed to the strengthening effect of numerous finely dispersed Guinier-Preston-Bagaryatsky (GPB) zones, in conjunction with the inhomogeneous formation of S phase on the dislocation loops.