The present invention provides a method for determining a precoding matrix indicator, user equipment, and a base station. The method includes: receiving a first reference signal set sent by a base station; determining, based on the first reference signal set, one or more intermediate matrices, and reporting, to the base station, a first index used to indicate the intermediate matrix; receiving a second reference signal set sent by the base station; and determining, based on the second reference signal set, a precoding matrix, and reporting, to the base station, a precoding matrix indicator used to indicate the precoding matrix, where the precoding matrix is a product W of two matrices W 1 and W 2, and W = W 1 W 2 , where W 1 is a block diagonal matrix, W 1 =diag{ X 1 , X 2}, a block matrix X i is a kronecker product of two matrices C i and D i , X i = C i Š— D i , i =1,2, and the matrix C i or the matrix D i is a function of the one or more intermediate matrices. In this way, transmission performance of an active antenna system can be improved.