1. A channel condition information feedback method for a terminal in a collaborative wireless communication network using a multiple input multiple output antenna system, the method comprising: grouping M adjacent base stations that are capable of collaborative communication; acquiring a maximum singular vector by estimating downlink channels from base stations belonging to a same group; selecting at least one weight vector v k,m,max for each of the M adjacent base stations most accurately representing to the maximum singular vector; selecting information corresponding to at least one complex variable g k,m for each of the M adjacent base stations, so that the result of combination of the at least one weight vector v k,m,max and the at least one complex variable g k,m is most accurately representing to the maximum singular vector; and feeding back the weight vector and the information, wherein, v _ k , max ⁢  g k , 1 ⁢ v k , 1 , max ⋮ g k , M ⁢ v k , M , max  v k,max is the maximum singular vector of H k , which is an n R Mn T collaborative channel matrix from the M adjacent base stations to a k th terminal, where n R is the number of receive antennas for each terminal, n T is the number of transmit antennas for each adjacent base station, and M is the total number of adjacent base stations in the same group; V k,m,max is the maximum singular vector of size n T 1 of a downlink channel H k,m , which is an n R n T complex channel matrix from an m th base station to a k th terminal; and g k,m is the complex variable, where √{square root over (g k,1 2 +g k,2 2 +. .. +g k,M 2 )}=1.