Al0.3CoCrFeNiBx(x= 0,0.01, 0.05, 0.1) high entropy alloys were fabricated by cold crucible levitation melting. The effect of addition of B on the microstructures of Al0.3CoCrFeNiBxalloys were studied using X-ray diffraction, electron backscatter diffraction, scanning electron microscopy with wavelength dispersive X-ray spectroscopy. The microhardness, friction and wear properties and compression properties of Al0.3CoCrFeNiBxalloys at room temperature were analyzed. The results show that Al0.3CoCrFeNi alloy is FCC structure. With increasing B content, the Cr2B precipitated phase increases gradually at the grain boundaries of FCC phase matrix, and the Cr2B phase gradually changes from granular distribution to continuous network distribution, resulting in the alloy microhardness, wear resistance and yield strength are gradually improved. It can be seen that the precipitation of Cr2B has significant dispersion strengthening effect, and the comprehensive performance of Al0.3CoCrFeNiB0.1is better.