In explosive experimentation,the collimator of conventional all fiber velocity interferometer can't availably collect diffuse reflection of high-speed object. With the superluminescent diode instead of the light source of conventional all fiber velocity interferometer,feasibility of all multi-mode fiber velocity interferometer is elementarily validated. The principle and the structure of all multi-mode fiber velocity interferometer are put forward and described. At last,comparing all multi-model fiber velocity interferometer with conventional all fiber velocity interferometer in experimentation of velocity measurement for speaker,the same result is acquired. It shows that the new interferometer can successfully probe the velocity profiles.