The invention discloses a dye wastewater treatment device based on an aluminum-based flocculating agent. The dye wastewater treatment device comprises a fixed barrel with an opening in the top and a rotating barrel, supporting columns are arranged at the four corners of the bottom of the fixed barrel respectively, a first motor is installed in the middle of the bottom of the fixed barrel through bolts, and the rotating barrel is connected with the output shaft of the first motor and located in the fixed barrel. Two water outlet holes are formed in the bottom of each side wall of the rotating barrel, a first filtering screen is installed in each water outlet hole, a fixing rack is welded to one side wall of the fixed barrel, and a vertical single-head air cylinder is installed on the supporting rack. A horizontal installation rod is welded to a piston rod of the single-head air cylinder, a second motor is fixedly arranged on the top of the installation rod through bolts, a vertical rotary shaft is connected with the output shaft of the second motor, and the rotary shaft is located in the rotating barrel. By means of the dye wastewater treatment device, the flocculent objects generated after waste water and the flocculating agent are reacted can be quickly removed and do not need to be manually dragged time and again, and the removal speed is fast.