The low-cost Ti-6Al-0.4V-1.2Fe alloy was subjected to isothermal compression experiments on the Gleeble 3800, and the deformation temperature was 775°C∼975°C and the strain rate was 0.01 s−1∼10 s−1. Based on the experimental data on thermal deformation, the microstructure evolution was studied and the constitutive equation was developed. The experimental results show that the flow stress increased with increasing deformation temperature and with the increase of the strain rate; the optimal deformation temperature of Ti-6Al-0.4V-1.2Fe alloy is 820°C∼950°C, and the strain rate is 0.01 s−1∼0.32 s−1; During hot deformation, the primary softening mechanism of this alloy is continuous dynamic recrystallisation. Compared with Ti-6Al-4V, the Ti-6Al-0.4V-1.2Fe alloy has better hot workability and better plasticity. Highlights A newly low-cost Ti-6Al-0.4V-1.2Fe alloy was designed based on the Kβ stability coefficient method, and the β stability coefficient was the same as that of Ti-6Al-4V. A study on the microstructure evolution in the process of hot deformation between Ti-6Al-0.4V-1.2Fe and Ti-6Al-4V alloys. A study on microstructure evolution and hot working process of a newly low-cost Ti-6Al-0.4V-1.2Fe alloy.