Abstract: As a critical research area for tropical marine biodiversity in China, Hainan Province hosts exceptionally rich molluscan resources, with documented species spanning 5 classes, 185 families, and 1129 species. This review synthesizes the diversity characteristics of mollusks on Hainan Province, evaluates progress in classical and systematic taxonomy, and identifies major limitations. Despite the favorable marine environments supporting diverse molluscan communities, current studies face challenges including morphological misidentification due to cryptic species and phenotypic plasticity, spatial sampling biases in coastal and deep-sea zones, habitat fragmentation from coastal urbanization, and technical constraints in molecular marker applications for phylogenetic resolution. To address these issues, future research should integrate environmental DNA metabarcoding for biodiversity monitoring, employ multidimensional data fusion combining ecological niche modeling and biogeochemical parameters, adopt phylogenomic approaches to construct high-resolution phylogenetic frameworks, and strengthen cross-regional collaborations to standardize conservation strategies.