To study Al on the properties of ferritic heat resistant steel phase change and the influence law, a new type of high aluminium ferritic heat resistant steel was prepared by adding Al element and adjusting additive Ni on the basis of T92 alloy composition. The relationship of ferritic heat resistant steel phase change temperature under different Al contents and heat treatment processes and quenching organization grain size, hardness and oxidation resistance was studied. The results show that the equilibrium phase transition point of the experimental steel increases with the increase of Al content, and the Ac1 and Ac3 temperature of the experimental steel becomes higher with the austenite grain size becoming larger. When the total amount of Al and Ni elements added in steel is 2.4 wt %, the austenite after quenching grain size is the smallest and the hardness is the largest. Adding 3 wt % Al to steel at 650 °C is more resistant to high temperature oxidation than adding 1 wt % Al. At 750 °C, the modified additive Ni plays a certain role. The larger the Al-Ni ratio, the stronger the oxidation resistance of the steel.