Abstract: Two kinds of δ-TRIP steels with different Al contents（Fe-10Mn-4Al-0.4C, Fe-10Mn-6Al-0.4C） were designed. The effects of Al content on the microstructure and phase content of δ-TRIP steel were studied by OM and EBSD techniques. The resuls show that when the content of Al increases from 4 % to 6 %, a large amount of δ ferrite appear in the structure, the overall grain size becomes larger, the ferrite content in the as-cast and hot-rolled microstructure increases, and the austenite content decreases. After hot rolling, the grain size is significantly thinner than that of as-cast steel, with the increase of Al content, the strength and elongation increase, and the comprehensive performance of the plastic product greatly improves compared with that of the as-cast steel, reaching a maximum of 15.64 GPa·%.