 In this study, we report on novel electroactive magnetic nanospheres for caesium separation and recovery, which is composed of a magnetic Fe3O4 nanosphere and electroactive cupric hexacyanoferrate coating. It is found that such electroactive magnetic Fe3O4@cupric hexacyanoferrate nanospheres show high ion exchange capacity, excellent selectivity, and rapid ion insertion kinetics. The electroactive magnetic Fe3O4@cupric hexacyanoferrate nanospheres can be regenerated by simply switching the potential of the magnetic electrode in a novel electromagnetic coupling regeneration system. Moreover, the capacity of electroactive magnetic Fe3O4@cupric hexacyanoferrate nanospheres towards Cs+ is nearly unchanged after 20 cycles, and a high regeneration efficiency of higher than 98% is maintained in each cycle. These novel electroactive magnetic nanospheres show high ion exchange capacity, excellent selectivity, rapid ion release kinetics, and remarkable electrochemical performance, and the problem of secondary pollution and resource waste is solved. Hence, they used to be a promising alternative to the conventional techniques for caesium ion capture from wastewater.