The constitutive equation of the material is an essential ingredient of any structural calculation. In this article, a phenomenological constitutive model is established to describe the dynamic deformation behavior of 30Cr2Ni4MoV steel in wide strain rate, strain, and temperature ranges. Also, the mathematical models to predict peak stress and corresponding strain were obtained. The stress-strain values predicted by the developed model well agree with experimental results, which confirmed that the developed constitutive equation gives an accurate and precise estimate for the flow stress of 30Cr2Ni4MoV steel.