The invention discloses a downlink MU_COMP (Multi-User_Coordinated Multiple Point) scheduling algorithm based on an improved chordal distance, which comprises the following steps that S1, edge cell users detect the strength of a current interference signal and feed back current signal interference noise ratios, and an activated user set in a coordinated transmission mode is determined according to the signal interference noise ratios; S2, a candidate user set and a selected user set are established, wherein the candidate user set comprises users in the activated user set; one of the users with the maximum F norm in the candidate user set is added to the selected user set, and the channel capacity of the users in the selected user set is computed; S3, a chordal distance between each user channel matrix in the candidate user set and a combined channel matrix in the selected user set is computed; S4, the user with the maximum chordal distance between the user channel matrix and the combined channel matrix in the selected user set is selected; S5, whether the users in the selected user set reach an upper user limit is judged, if so, S2 is skipped to, and if not, S6 is skipped to; and S6, block diagonalization precoding matrixes are designed for the edge cell users in the selected user set respectively, and a coordination base station uses the block diagonalization precoding matrixes to perform combined precoding and sending on the edge cell users.