Comprehensive SummaryHyperbranched polymers with unique topological structures, large number of branching sites and terminal groups have attracted much attention, and are expected to possess advanced functionalities compared with their linear polymer counterparts. The development of hyperbranched polymers is hence highly desired but challenging, especially for sulfur‐containing polymers which are attractive metal absorbents, optical materials, dielectric materials, and self‐healing materials. In this work, six hyperbranched polythioamides with various topological structures, well‐defined repeating units, satisfying yields (up to 99%), and high molecular weights (up to 101400 g/mol) were successfully designed and synthesized from the catalyst‐free multicomponent polymerization of elemental sulfur, aromatic alkynes and aliphatic amines, through different monomer combination strategies based on the designed three‐ or four‐functional alkyne and amine monomers. The hyperbranched polythioamides possess unique luminescence property, and strong affinity toward Hg2+, which can be utilized in the fluorescence detection of Hg2+, as well as mercury removal from aqueous solutions with high efficiency of 99.99% and low mercury residue of 0.1 ppb. Hyperbranched polythioamides with unique structures may be developed to a group of fascinating materials and find their potential applications as metal absorbents and optoelectronic materials.