To reduce the cost of nanocomposites and improve the dispersion of nanoparticles, Al₂O_3np/SiC_np/Al hybrid nanocomposites are fabricated by combining liquid-state blowing and ultrasonic-assisted casting. The average grain size of the matrix decreases to 39 μm in Al₂O_3np/SiC_np/Al, which shows improvements of approximately 118% and 26% as compared to those of Al₂O_3np/Al and SiC_np/Al, respectively. X-ray Diffractometer (XRD) results confirm the presence of SiC_np and Al₂O_3np in hybrid nanocomposites. The dispersed SiC_np and Al₂O_3np are homogeneously distributed in the matrix and no clusters consisting of SiC_np and Al₂O_3np exist in the microstructure. Theoretical analyses also verify that there is little possibility for clusters to form in the melt. Good bonding between nanoparticles and Al is demonstrated. Neither cavities nor reaction products exist at the interface. The ductility and the strength of Al₂O_3np/SiC_np/Al are improved. The improvement in yield strength of Al₂O_3np/SiC_np/Al, in comparison with that of A356, is about 45%.