A method, system, and device for determining a pre-coding matrix that can be used to determine an integral pre-coding matrix. The method of the embodiments of the present invention comprises: a user device determines a third pre-coding matrix according to a first pre-coding matrix and a second pre-coding matrix; an integral pre-coding matrix is determined according to the determined third pre-coding matrix, the integral pre-coding matrix being a sub-matrix of the third pre-coding matrix; integral pre-coding matrix information is determined according to the integral pre-coding matrix, and is transmitted to the network device. Because the user device determines that the integral pre-coding matrix is a sub-matrix of the third pre-coding matrix, which is determined according to the first pre-coding matrix and the second pre-coding matrix, the integral matrix code can be determined, thereby enhancing data transmission efficiency and system performance.