Chemical communication is crucial in ecosystems with complex microbial assemblages. However, due to archaeal cultivation challenges, our understanding of the structure diversity and function of secondary metabolites (SMs) within archaeal communities is limited compared to the extensively studied and well-documented bacterial counterparts. Our comprehensive investigation into the biosynthetic potential of archaea, combined with metabolic analyses and heterologous expression, has unveiled the previously unexplored biosynthetic capabilities and chemical diversity of Archaeal SMs. This represents the first reported instance of heterologous expression of archaeal SMs. We have identified twenty-four new lanthipeptides of RiPPs exhibiting unique chemical characteristics, including a novel subfamily featuring an unexplored type with diamino-dicarboxylic (DADC) termini, largely expanding the chemical landscape of Archaeal SMs. The maturation process of this noncanonical DADC lanthipeptide deviates from classical ones by cleaving amino acids within the thioether rings. This sheds light on the biosynthetic novelty of archaeal metabolites and emphasizes their potential as an untapped resource for SMs. Interestingly, archaeal lanthipeptides exhibit haloarchaea-specific antagonistic activity and enhance the host's motility, facilitating the archaeal interaction with biotic and abiotic environments. Our discoveries broaden our understanding of archaeal chemical language and provide promising prospects for future exploration of SM-mediated interactions in this domain.