A model is presented for the prediction of critical cutting conditions of adiabatic shear in orthogonal high speed cutting. Considering the influence of compression stress, a critical criterion of adiabatic shear in orthogonal high speed cutting is given by linear perturbation on the compress-shear deformation continuum mechanics basic equations of the primary shear zone. Combining with the relationship of cutting conditions and deformation ones, also the materials constitutive realtionship, a pridiction model, which expressed by cutting conditions and materials properties is established. As an example, the adiabatic shear critical conditions of AISI 1045 steel are predicted, and cutting experiments are performed. The prediction results are consistent with that of experiments.