Abstract: The time-reversal mirror's refocus effects are studied based on the point of view of the channel theory, particularly, Vector Time-reversal Mirror (VTRM) space-time filtering technology is introduced in this paper. The results of VTRM's spatial match characteristic, processing gain, detecting ability and robust behavior show that VTRM produces focusing in time as well as in space. Focusing in space occurs because the coherence of multipath channel is applied and focusing in time occurs because the difference of the correlation of acoustic pressure and particle velocity is applied. This kind of VTRM technology not only has higher performance and precision, but also is more robust and stable than conventional time-reversal technology.