The present invention relates to a wireless communication system, and more particularly, to a method and device for performing or supporting NIB coordinated multi-point (CoMP) transmission in a wireless communication system. The method for performing NIB CoMP transmission in the wireless communication system according to an embodiment of the present invention may include: transmitting a first-type signal including one or more sets of first CoMP hypotheses from a first network node to a second network node; and receiving at the first network node a second-type signal including one or more sets of second CoMP hypotheses from the second network node. The first-type signal and the second-type signal are defined as having the same information format, and the first-type signal or the second-type signal may be identified based on a specific bit of the information format.