Remineralization is a common strategy for the repair of early demineralized tooth enamels, but the harsh dynamic oral environment often hampers its efficacy. Rapid remineralization is expected to address this challenge, however, the stabilizers of remineralization materials often resist their transformation required for repair. Here, by dissolving the ions of calcium and phosphate in glycerol-dominant solvents, we obtain the calcium phosphate clusters (1–2 nm), which are stabilized by glycerol (with high viscosity and affinity to clusters), but can perform a fast enamel repair via the water-triggered transformation in both static and dynamic environments. Upon the in vitro and in vivo (female Sprague-Dawley rats) studies, the clusters swiftly enter the nano-/micro-sized enamel defect sites, then form a compact hydroxyapatite repair layer within a short time (30 min, much faster than the conventional materials), and significantly recovers mechanical properties. This material is promising for large-scale preparation and applications in dental remineralization. Using remineralization materials to grow hydroxyapatite crystals on the surfaces is a common strategy for the repair of early demineralized tooth enamels but often stabilizers used for reparation and storage slow down the mineralization process. Here the authors use glycerol stabilized calcium phosphate cluster, which can perform a fast enamel repair via water-triggered transformation.