A method for acquiring channel information, comprising: for one subband, a User Equipment, UE, acquiring Rank Indicator, RI, of a current channel, wherein a rank, υ, of said current channel is indicated in the RI, and the υ is a positive integral number not greater than 8; wherein the user equipment determining a total number of at least one Precoding Matrix Indicator, PMI, required to be fed back to a base station according to the υ, and transmitting the at least one PMI corresponding to the total number and the RI to the base station, wherein the at least one PMI corresponding to the total number and the RI are used by the base station to acquire channel information of said subband; and wherein when the total number is 1, the at least one PMI corresponding to the total number is used for obtaining one Precoding Matrix, and when the total number is greater than 1, the at least one PMI corresponding to the total number is used for jointly obtaining one Precoding Matrix, the total number is an integral number; wherein the step of the user equipment determining the total number of the at least one PMI required to be fed back to the base station according to the υ comprises: when the υ is greater than or equal to N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m; and when the υ is less than N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m+1; wherein N0 is an integral number greater than 0 and less than or equal to 8, and m is an integral number determined according to a level of feedback precision of the user equipment. for one subband, a User Equipment, UE, acquiring Rank Indicator, RI, of a current channel, wherein a rank, υ, of said current channel is indicated in the RI, and the υ is a positive integral number not greater than 8; wherein the user equipment determining a total number of at least one Precoding Matrix Indicator, PMI, required to be fed back to a base station according to the υ, and transmitting the at least one PMI corresponding to the total number and the RI to the base station, wherein the at least one PMI corresponding to the total number and the RI are used by the base station to acquire channel information of said subband; and wherein when the total number is 1, the at least one PMI corresponding to the total number is used for obtaining one Precoding Matrix, and when the total number is greater than 1, the at least one PMI corresponding to the total number is used for jointly obtaining one Precoding Matrix, the total number is an integral number; wherein the step of the user equipment determining the total number of the at least one PMI required to be fed back to the base station according to the υ comprises: when the υ is greater than or equal to N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m; and when the υ is less than N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m+1; wherein N0 is an integral number greater than 0 and less than or equal to 8, and m is an integral number determined according to a level of feedback precision of the user equipment. when the υ is greater than or equal to N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m; and when the υ is less than N0, the user equipment determining that the total number of the at least one PMI required to be fed back to the base station is m+1; wherein N0 is an integral number greater than 0 and less than or equal to 8, and m is an integral number determined according to a level of feedback precision of the user equipment.