In this study, the (Fe50Mn30Co10Cr10)97Al3 high-entropy alloy (HEA) was designed by adding the Al element based on the two-phase metastable Fe50Mn30Co10Cr10 HEA. Then the HEA was treated by rolling and annealing, and the effects of annealing temperature on recrystallization behavior, annealing twin evolution and the mechanical properties of the alloy were studied. The results show that with the increase of annealing temperature, partial recrystallization, full recrystallization and grain growth occur in the alloy. After annealing, the HEA exhibits the high recrystallization temperature (0.59 Tm) and the grain coarsening temperature (700 ℃) due to the severe lattice distortion effect and hysteresis diffusion effect of the HEA. A Large number of annealing twins are formed in the alloy annealed at 600~700 ℃; with the further increase of annealing temperature (800~900 ℃) , the content of annealing twins drop significantly due to the migration of grain boundaries or twin boundaries. Uniaxial tension results show that the alloy annealed at 700 ℃ has good comprehensive mechanical properties, with a tensile strength of 730 MPa and a uniform elongation of 50.5%. At the same annealing temperature, the number of annealing twin variants in a single grain is related to its grain size, it is easy to form single annealing twin variant in the small-sized grains, and to form multiple annealing twin variants in the large-sized grains.