The research of transition metal dichalcogenides (TMDCs) in the field of electromagnetic wave absorption (EMW) has been increasing. Designing and fabricating electromagnetic wave absorbing materials with light weight, small thickness, wide bandwidth and high strength is still a big challenge. In this paper, the wet impregnation method was selected to modify Co(CO3)0.5(OH)·0.11H2O-derived CoS2 hollow sea urchins to achieve the purpose of optimizing performance. Co2+ was precipitated in urea aqueous solution to produce Co(CO3)0.5(OH)·0.11H2O, followed by two pyrolysis to obtain hollow sea urchin-like CoS2. Finally, sulfided heterobimetals are doped during hydrogen-argon gas heat treatment to generate heterocomponents. The results show that the FeCoS2-doped hollow sea urchin CoS2 has an ultra-high EMW absorption capacity with an effective absorption bandwidth of 5.76 GHz (2.12 mm) and a minimum reflection loss value of -75.23 dB (1.87 mm). The hollow sea urchin structure and heterobimetallic sulfide hybridization can improve the interfacial polarization, which provides a clear direction for the development of TMDCs.Graphical abstract: The electromagnetic wave absorption ability is enhanced through the unique three-dimensional hollow sea urchin sphere structure and the synergistic effect of CoS2 and FeCoS2 nanoparticles.