This study investigated the effect of annealing temperature (Ta=800–1000 ℃) on the microstructure and mechanical properties of Fe-25Mn-10Al-1.1 C-(0,0.48)V (wt%) austenitic low-density steels. The results show that Ta has significant influence on the microstructures of the two tested steels. Considerable amount of ferrites and κ-carbides appeared on grain boundaries due to precipitation reaction (γ→α + κ) when annealed at a lower temperature of 800 ℃, and the V addition would promote the precipitation reaction and cause an increase of ferrite content when annealed at no more than 900 ℃. The content of VC reached a maximum at Ta= 900 ℃, which also significantly inhibited the formation of κ-carbide and delayed the recrystallization besides grain refinement for the V-added steel. Moreover, VC also inhibited the development of the Σ3n (n = 1,2,3) boundaries at Ta of no more than 900 ℃. Ultra-high yield strength of 1120 MPa was obtained when the V-added steel was annealed at 900 ℃ mainly due to the drastic VC precipitation. The present work provides a promising strategy to enhance the yield strength of austenitic low-density steel via tailoring Ta and the addition of V.