Abstract: A self-developed Al-Fe-Mn aluminum alloy sheet was hot-rolled and cold-rolled to 2 mm, and then isothermal annealing was carried out by heating the sheet to 340-400 ℃. By comparing the hardness variation of aluminum alloy sheets under different annealing temperatures and holding time conditions, and combining with metallographic examination, the temperature and time of recrystallization transition under certain holding time and constant temperature were determined. The recrystallization activation energy of the sheet was calculated through Arrhenius formula. The results have revealed that the recrystallization time is 13 minutes when the annealing temperature is 340 ℃, and the recrystallization time is reduced to 8 minutes when the temperature is increased to 360 ℃. The recrystallization occurs in 3 minutes when the temperature is further increased to 380 ℃. It is found that the calculated recrystallization activation energy is 115.9 kJ/mol.