In this study, a new severe plastic deformation method, equal channel angular pressing (ECAP), was applied to strengthen a discontinuously TiB+TiC reinforced titanium alloy. The microstructural evolution mechanism during severe plasitic deformation processing was systematicly studied. Special attention was focused on the grain refinement, the deformation mechnism and formation mechnism in the preparation of ultrafine grain composite. The results indicated that the refinement of TiB fibers and TiC particles could be obtained, as well as the grain size of the matrix alloy. With the increasing of ECAP pass numbers, the clustered long TiB fibers and TiC big particles were also homogenized in the matrix, resulting in the increase of the mechanical properties. The tensile strength is up to 1205MPa, and the elongation improves comparing with the first ECAP pass.