The high temperature interfacial bonding characteristics of intumescent fire-retardant/anticorrosion coating system with substrate were key factors affecting the fireperformance in practical applications. In this paper，the high temperature interfacial characteristics of commercial fire-retardant coatings in different systems were systematically studied by adhesion test，scanning electron microscope（SEM）， high temperature image andsmall-scale fire performance test. The results showed that JSP water-based fire-retardantcoating exhibited obvious high temperature interface incompatibility defects under specificsystems，leading to fire resistance failure and the fire resistance limit decreased by about 42%.While SSP water-based fire-retardant coating exhibited good high temperature interfacecompatibility in each system and the fire resistance limit of different systems was maintained at50-60 minutes. Combined with high temperature image analysis，the expansion form of the twocoatings at high temperature and the interface bonding area after expansion significantly affecttheir high temperature interface compatibility.