High-entropy alloy (HEA), as a class of new alloy materials characterized by high stability, excellent specific strength and corrosion resistance, has attracted much attention in the field of aluminum matrix composites (AMCs). To study the effect on microstructure and mechanical properties of aluminum alloys, AlCoCrFeNi HEA particles reinforced ADC12 composites were fabricated by high energy ultrasonic casting process. Subsequently, the effect of HEAs addition on the microstructure and mechanical properties of ADC12 alloys was investigated. Results show that the added HEA particles are tightly bonded to the aluminum matrix. The Al₂Cu phase in the matrix is refined. Meanwhile, the tensile strength and microhardness of the alloys with the addition of HEA particles are significantly improved. The yield strength and ultimate tensile strength of as-prepared composites with 12wt% HEAs are increased by 16.9% and 21.9% compared with those of the matrix, respectively. The wear rate of the composites is also decreased due to the enhancement of microhardness under applied load of 20 N. It is mainly attributed to the load transfer strengthening, dislocation proliferation and the optimization of the microstructure.