3D hierarchical network ultralight RGOF/MoS2 samples: design, production and their extraordinary comprehensive microwave absorption properties. Display omitted Using previous models and theories to construct and develop high-efficient microwave absorbers (MAs) should be a strategic and effective ways to optimize the electromagnetic wave attenuation. Herein, the ultralow density and flexible graphene oxide foam (GOF) and reduced graphene oxide foam (RGOF)/MoS2 nanosheets were designed and fabricated by the method of chemical vapor deposition and hydrothermal reaction. The obtained GOF and RGOF/MoS2 samples exhibited very excellent microwave absorption properties while their densities were merely 0.0082 and 0.0084 g•cm−3, respectively. More importantly, benefiting from the excellent synergistic effect between RGOF and MoS2, the designed RGOF/MoS2 well inherited the combined advantages of GOF and MoS2 in terms of strong absorption abilities, broad absorption bandwidth and thin matching thicknesses. The values of minimum reflection loss and effective frequency bandwidth for RGOF/MoS2 sample could reach up to −62.92 dB with the matching thickness of 2.27 mm and 4.48 GHz with the matching thickness of 2.12 mm, which were very desirable for high-performance MAs. Moreover, the obtained results indicated that the microwave absorption properties of RGOF/MoS2 sample could be further optimized by regulating the MoS2 content. Therefore, a new and effective strategy was proposed to develop high efficiency MAs with ultra-lightweight, wide-band, thin thickness and strong absorption capabilities.