A method for multi-beam forming based on joint receiving and transmitting end information is provided. The method includes: a transmitting end decomposing a channel matrix H using a geometric mean decomposition (GMD) way to obtain a unitary matrix P; the transmitting end using the unitary matrix P as a weight matrix of GMD beam forming and executing multi-beam forming processing on an original transmission signal x. The present invention also provides a system for multi-beam forming based on joint receiving and transmitting end information, and a transmitting device and receiving device for supporting multi-beam forming based on joint receiving and transmitting end information. By using geometric mean decomposition way to decompose the channel matrix H, the sub channels corresponding to various beams obtain the equal gain. When the channel is ill-conditioned, the channel equalization will not interfere with searching the perturbation vector, thereby avoiding the performance degradation.