In this study, an alkali-activated binders (AABs) with excellent high-temperature performance on the surface of iron plate was prepared by using alkali-activated slag as the main material, modulating the addition of filler CaCO3 particles (CC), and using iron plate (Q235) as the coated substrate. Through characterization and analytical tests such as compressive/flexural/bond strength, XRD, TG/DSC, SEM/EDS and OM, the results showed that the bonding effect between AABs and Q235 was mainly influenced by both the internal stress of AABs and the diffusion effect of the interfacial atoms. Under the condition of not adding CC, the internal stress of AABs was much larger than the interfacial bonding force, thus causing warping and spalling at room temperature. Microscopic characterization revealed that the addition of CC reduced internal stresses and microcracks, resulting in improved interfacial bonding. Excellent bonding properties were obtained by adding 10 g of CC, with a compressive/flexural/bond strength of 6.98/0.68/0.10 MPa, and a linear shrinkage of 2.22 % after calcination at 700 °C. The crystalline transition from CaCO3 and calcium silicate hydrate to akermanite-gehlenite, merwinite and lime does not begin to take place until the calcination temperature reaches 800 °C. The failure mechanism of AABs at room temperature and high temperature was studied to provide a basis for the optimization of existing AABs and the development of high-performance AABs.