Molybdenum disulfide (MoS2) has attracted much attention in the field of electromagnetic wave (EMW) absorption due to its high specific surface area and unique electronic structure, but its high conductivity leads to poor EMW absorption performance. To address this issue, this work introduces CuxSy nanoparticles and constructs a unique CuxSy-MoS2 heterostructure to achieve appropriate impedance matching and attenuation capabilities. By regulating CuxSy nanoparticles, the dielectric loss capacity of heterostructure is adjusted. As a result, CuxSy-MoS2 exhibits excellent EMW absorption performance at low, medium and high frequencies. The CuxSy-MoS2 heterostructure shows a reflection loss (RL) of -72.77 dB at a frequency of 12.68 GHz, with a matching thickness of only 1.99 mm, surpassing most metal sulfide heterostructures. Moreover, it also exhibits a wide effective absorption bandwidth (EAB), reaching 5.1 GHz (12.9~18.0 GHz) at 1.73 mm. This work provides a new strategy for designing MoS2-based absorption materials with strong absorption, broadband and thin matching thickness.