This review has systematically assessed the critical technologies of impurity removal fans in segmental sugarcane harvesters, highlighting their impact on minimizing harvester impurity rates. The analysis was conducted from three perspectives: Firstly, the physical properties of flexible sheet-like materials were thoroughly examined, including the methodologies for material parameter measurement, the utilization of technical approaches, and the constraints of existing methods. Secondly, the operational mechanisms of impurity removal fans were elucidated, encompassing their working principles, research subjects, and technical methodologies, and compared with the mechanisms of analogous fluid machinery. Lastly, a review of the structural design and parameters of impurity removal fans was undertaken, analyzing the interplay between operational modes, structural optimization designs, and aerodynamic characteristics. The review identified key issues in the design and performance of impurity removal fans and recognized the challenges in technological advancement. Through this triadic analytical framework, the review has identified salient design and performance deficiencies within existing impurity expulsion fan technologies and has underscored the formidable challenges confronting technological evolution in this domain. Synthesizing these insights, the review proffered prospective research vectors and avant-garde technological interventions poised to augment the operational efficacy of impurity expulsion fans, with the overarching goal of enhancing the operational proficiency of sugarcane harvesting machinery.