OBJECTIVE Dentin hypersensitivity (DH) is a common oral disease with approximately 41.9% prevalence. Reconstruction of dental hard tissues is the preferred treatment for relieving DH. Here, we applied biomineralization method using oligopeptide simulating cementum protein 1 (CEMP1) to regenerate hard tissues on demineralized dentin. METHODS The self-assembly and biomineralization property of the oligopeptide were detected by scanning electron microscopy (SEM), circular dichroism spectroscopy, and transmission electron microscopy. Oligopeptide's binding capacity to demineralized dentin was evaluated by SEM and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Remineralization was characterized using SEM, ATR-FTIR, X-ray diffraction, and nanoindentation. Oligopeptide's biocompatibility was evaluated using periodontal ligament cells. RESULTS Oligopeptides self-assembled into nano-matrix and templated mineral precursor formation within 24 h. Moreover, oligopeptide nano-matrix bound firmly on demineralized dentin and resisted water rinsing. Then, bound nano-matrix served as a template to initiate nucleation and transformation of hydroxyapatite on demineralized dentin. After 96 h, oligopeptide nano-matrix regenerated an enamel-like tissue layer with a thickness of 15.35 μm, and regenerated crystals occluded dentin tubules with a depth of 31.27 μm. Furthermore, the oligopeptide nano-matrix had good biocompatibility when co-cultured with periodontal ligament cells. CONCLUSIONS This biomimetic oligopeptide simulating CEMP1 effectively induced remineralization and reconstructed hard tissues on demineralized dentin, providing a potential biomaterial for DH treatment.