The utility model discloses a separated three-frequency loudspeaker box. The loudspeaker box comprises a box body, a high pitch unit, an alto pitch unit, and a low pitch unit. A support is disposed on the box body and the low pitch unit is mounted in the box body. The alto pitch unit and the high pitch unit are mounted on the support. The high pitch unit is arranged under the alto pitch unit. The advantages of the separated three-frequency loudspeaker box are that the three sound generating units are separately mounted, that the high pitch unit and the alto pitch unit are mounted on the support, that the high pitch unit and the alto pitch unit have large installing space, and that the phases of the three sound generating units are easy to adjust, being beneficial to promotion of tone quality.