The utility model discloses a differential distribution tank used for a vibration forming machine, which comprises a box body. A power input shaft and a power output shaft are respectively arranged at both sides of the box body; the power input shaft is connected with an inner output shaft and an outer output shaft through a gear system and a driving shaft. The utility model is characterized in that a sun wheel is arranged outside the driving shaft; an inner and outer driving gear is arranged outside the sun wheel; a planetary wheel group is arranged between the sun wheel and the inner and outer driving gear; the planetary wheel group is consolidated on a revolution adjustment disk. Because the utility model adopts the structure to amplitude modulation, the differentials of a front stage and a back stage are realized by a planetary wheel mechanism, and the change of a phase angle of the output shaft is exactly operated by a worm gear and rod mechanism, equipment is stable and reliable when the equipment is modulated, impact is small when the utility model is running, the quality of formed products is improved, and the functions of synchronous speed change and distribution are realized. The utility model has the advantages of reasonable design, simple and reliable structure and convenient maintenance and adjustment.