Abstract: The linear ubiquitin chain assembly complex (LUBAC), composed of heme-oxidized IRP2 ubiquitin ligase 1-interacting protein (HOIP), haem-oxidized IRP2 ubiquitin ligase-1(HOIL-1), and SHANK-associated RBCK1 homology-domain-interacting protein (SHARPIN), and its specific deubiquitinating enzyme OTULIN, regulates the dynamic balance of Met1-linked linear ubiquitination and maintains ubiquitin signaling homeostasis. Their precise interaction plays a central role in the regulation of nuclear factor-κB (NF-κB) and type I interferon signaling, inflammatory response, and cell survival and death. Dysregulation of the LUBAC-OTULIN axis can lead to aberrant immune and inflammatory signaling, immunodeficiency, and dysregulation of receptor-interacting protein kinase 1-mediated apoptosis or necroptosis. Genetic defects in OTULIN and LUBAC are associated with rare autoinflammatory diseases such as OTULIN-related autoinflammatory syndrome (ORAS) and HOIP/HOIL-1/SHARPIN deficiency, respectively, with complex clinical phenotypes and gene dose correlation. Current treatments primarily rely on glucocorticoids and tumor necrosis factor inhibitors, and hematopoietic stem cell transplantation has shown potential curative value in some patients with severe ORAS. This review summarizes the molecular composition, interaction mechanisms, and pathogenic roles of the LUBAC-OTULIN axis in rare autoinflammatory diseases, providing reference for the development of targeted therapeutic strategies.