The invention relates to a foreign fiber separating device, in particular to a tower type multi-stage electrostatic zero-damage foreign fiber separating device. The tower type multi-stage electrostatic zero-damage foreign fiber separating device comprises a rack, a motor, a feed inlet, a conveying mesh belt, a transmission gear, a high voltage electrostatic generator, an electrode plate, a sawtooth-shaped electrode, a seed cotton sliding plate, a hairbrush, a foreign fiber conveyor belt and a foreign matter negative-pressure output pipeline. Compared with the prior art, by adopting a tower type multi-stage electrostatic separating principle, the electrical charge time of foreign fiber during a separating process is longer, foreign fiber removing on multiple a plurality of contact surfaces of cotton seeds is realized through falling and rolling of the cotton seeds, and the separating efficiency is higher; a rapid collection of impurities such as dust and hairs can be completed while the foreign fiber is collected by using the foreign matter negative-pressure output pipeline, and secondary pollution is avoided; meanwhile, a zero-damage separation on the foreign fiber of the cotton seeds is realized through adopting modes of static electricity and falling and rolling of the cotton seeds.