［Objective/Significance］ Developing highly efficient flame-retardant technology iscrucial for enhancing the safety of epoxy resin（EP） coatings. This review aims to systematicallysummarize the design strategies，flame-retardant mechanisms，and research progress of polyhedral oligomeric silsesquioxane（POSS）-based hybrid flame retardants（X@POSS）.［Analysis/Discussion/ Progress］ Based on the differences in the“X”components，the construction strategies，flame-retardant efficiency，and effects on the thermal stability and mechanical properties of EP compositescoatings are systematically reviewed for phosphorus-based@POSS，carbon-based@POSS，metal/metal oxide@POSS， MOF@POSS， and multi-component@POSS. X@POSS hybrid flame retardants significantly enhance the limiting oxygen index（up to 38.2%）and UL-94 rating（V-0 level）of EP coatings，while effectively reducing the heat release rate（by up to 78.0%） and smoke density. Moreover，many systems also improve the thermal stability and mechanical properties of the materials.The flame-retardant mechanism primarily stems from the synergistic effects of gas-phase radical quenching and condensed-phase catalytic char formation with barrier protection.［Conclusion/ Prospect］ X@POSS represents an effective pathway for the high-performance development of EP coatings. Future research should focus on precise molecular synthesis，enhanced environmental compatibility，and industrial application.