The segregation behavior and the deformation mechanism of Ti14, a new typical burn resistant α+Ti2Cu alloy were investigated, during semi-solid forging at different temperatures. The results reveal that semi-solid temperature will affect the content and the distribution of liquid phase evidently. Upon increasing of temperature, the liquid phase distribution transforms from discontinuity to continuity at grain boundaries, and finally a type of net-structure is formed. Moreover, the macro-segregation of liquid and solid phases occurs during the semi-solid forging, which leads to a change of the main deformation mechanism from center to edge of the sample. The relationship of macro-segregation of liquid/solid phases and the main deformation mechanism was also discussed by a phenomenological model.