Abstract: The effects of recrystallization annealing temperature on the microstructure and mechanical properties of Ti5211 titanium alloy plates are studied. The results show that with the increasing of annealing temperature, primary α phase tends to change from long columnar to be equiaxed, and the secondary α phase precipitates gradually and grows up. After being annealed at 950 ℃, the microstructure is a bimodal structure with lamellar α phase, and after being annealed at 965 ℃, it is an equiaxed structure. With the increasing of annealing temperature, the room temperature strength decreases, the room temperature plasticity shows no obvious change, and the impact toughness first increases and then decreases.