Precise detection and effectively eliminating mercury pollution in aqueous solutions remains an onerous task for protecting the public health and environment. In this paper, porous MoS2 composite aerogel-supported Au nanoparticles with strong mercury affinity have been fabricated to deal with this problem. Such composite aerogels are fabricated using graphene oxide (GO)-doped MoS2 sheets as the feedstock by hydrothermal assembly and then the Au and Fe3O4 nanoparticles (NPs) embed between the GO-doped MoS2 sheets through coordination. The resultant porous Au/Fe3O4/MoS2CAs aerogel not only can sensitively detect mercury(II) in aqueous solution by a colorimetric method with a low detection limit (3.279 nM) but also can exhibit a super mercury adsorption capacity (∼1527 mg g–1) and fast desorption ability. After magnetic separation, the Hg2+ levels decreased from 10 ppm to 0.11 ppb within a few minutes, which is far below 2 ppb. In addition, Au/Fe3O4/MoS2CAs could be successively recycled more than 10 times with high removal efficiency (>95%). The excellent performance of the composition aerogel profits from its 3D interconnected macroporous framework as well as strong coupling between Au nanoparticles and MoS2 nanosheets, rendering it a potential detection and adsorbent material for mercury(II) from contaminated water for environmental remediation.Keywords: Detection; Mercury(II); MoS2 composition aerogel; Removal; Three-dimensional