Embodiments of the present invention provide a method for determining a precoding matrix indicator, a receiving device, and a sending device. The method for determining a precoding matrix indicator includes: selecting, by a receive end, a precoding matrix W from a codebook based on a reference signal sent by a transmit end, where the precoding matrix W is a product of two matrices W1 and W2, where the W1 includes NB block matrices Xi, NB≥1, and the W1 is indicated as: W1=diag{X1, . . . , XNB}, where 1≤i≤NB, and a column xi,j of each block matrix Xi is a Kronecker product of a first vector Aij and a second vector Bij, that is, xij=Aij⊗Bij; and sending, by the receive end, a precoding matrix indicator PMI corresponding to the precoding matrix W to the transmit end, so that the transmit end obtains the precoding matrix W according to the PMI.