<p>High-temperature curing is extensively employed for precast concrete components. To investigate the impacts of high-temperature curing and nanoparticles on the dynamic mechanical properties of concrete, this study investigates how high-temperature curing and nanoparticles (nano-CaCO₃ and nano-SiO₂) influence concrete’s dynamic mechanical properties by evaluating dynamic elastic modulus (<i>E</i>_<i>d</i>) and flexural fatigue under standard, steam, and hot water curing. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) analysis revealed nanoparticle enhancement mechanisms. Results show high-temperature curing markedly boosts early <i>E</i>_<i>d</i> but later reduces it, and increases the fatigue life’s dispersion, detrimental to later dynamic mechanical properties, with steam curing causing the most adverse effects. Incorporating 1% nano-CaCO₃ and 2% nano-SiO₂ enhance the early <i>E</i>_<i>d</i> under high-temperature curing, and fully repair late <i>E</i>_<i>d</i> and flexural fatigue performance losses of concrete. Both high-temperature curing and nanoparticles facilitate early cement hydration, generating C-S-H gels with low Ca/Si ratios for denser microstructure. However, high-temperature curing induces uneven distribution of hydration products, insufficient hydration, increased porosity and cracking, and delayed ettringite in the later microstructure of concrete, raising the Ca/Si ratio of the C-S-H gels and reducing dynamic mechanical properties. Nanoparticle addition mitigates these deteriorations, maintaining good later microstructures and dynamic mechanical properties.</p>