In the long process of evolution, invertebrates gradually developed an innate immune system characterized by receptor recognition, signal transduction, and immune response to clear apoptotic cells or pathogenic microorganisms. Scavenger receptors (SRs) are transmembrane pattern recognition receptors located on the cell surface that play an important role in the innate immune response of invertebrates. SRs participate in the recognition of non-self targets in the immune responses and regulate antimicrobial peptide synthesis and phagocytosis through downstream signal cascades. In this review, the types and structures of SRs in invertebrates and the regulatory mechanisms involved in the innate immunity of invertebrates were introduced, and the remaining problems in the study of SRs in invertebrates were discussed.