Abstract: Single-pass hot compression tests were carried out on Al and Ti composite strengthened martensitic precipitation-hardened steel using Gleeble-3800 thermal simulation tester, the effect of deformation temperature and strain rate on dynamic recrystallization were investigated. In the process of hot compression, the deformation amount is 70%, the deformation temperature is 850 ℃-1150 ℃, and the strain rate is 0.1 s^-1-10 s^-1. The true stress-strain curves of Al and Ti composite reinforced steel were analyzed, and the constitutive equation and hot working diagram of Al and Ti composite reinforced steel were obtained. The critical condition of dynamic recrystallization of Al and Ti composite reinforced steel was analyzed by θ-σ graph. The influence of deformation temperature and strain rate on the thermal deformation of Al and Ti composite reinforced steel was studied by combining the characterization of OM and EBSD. The results show that fine recrystallization grains can be obtained at low temperature and high strain rate, but the recrystallization is incomplete. The complete recrystallization structure can be obtained by increasing the recrystallization temperature and decreasing the strain rate. Through the stress-strain curve, the constitutive equation of forged Al and Ti composite reinforced steel is obtained, and the activation energy of hot compression deformation Q=476.86 kJ/mol is obtained. The optimum working zone is as follows: the thermal compression deformation temperature is 1000 ℃-1100 ℃, and the thermal compression processing map is 1 s^-1-10 s^-1.