Abstract: Al_0.1Cr_0.5FeMn₂ Ni_0.5 high-entropy alloy was prepared by vacuum arc-melting. After homogenization treatment and hot rolling, the alloy was annealed at 1100 ℃ for different time to study the effect of annealing time on the microstructure and tensile properties. The results show that microstructure of the hot-rolled alloy consists of fibrous matrix grains and coarse granular σ phases. The matrix grains are composed of FCC and BCC solid-solution phases. After annealing treatment, all samples underwent complete recrystallization, and the microstructure consisted of equiaxed matrix grains and granular σ phases. As the annealing time prolongs, the average size of the matrix grains and the content of BCC solid-solution phases in them both increase, while the average size of granular σ phases decreases. The tensile properties of the alloy at room-temperature and low-temperature（-196 ℃） exhibit similar changes with the prolongation of annealing time. When the annealing time are 5 min and 15min, the alloy has good room-and low-temperature plasticity,and the corresponding tensile fracture surfaces exhibit typical ductile fracture characteristics. The study for the first time found the presence of good plasticity in Al-Cr-Fe-Mn-Ni based high-entropy alloys, which can provide references for the development of low-cost high-entropy alloys with better comprehensive mechanical properties in the alloy system.