Concrete has exceptional mechanical properties and durability. Nevertheless, conventional curing methods are ineffective in addressing the issues of autogenous shrinkage and cracking during its early stages. Internal curing technology can effectively enhance the internal moisture distribution of concrete, mitigate shrinkage cracking, and improve its durability. This paper investigates the internal curing mechanism of concrete and analyzes its influence on the durability of concrete. Incorporating pre-wetted lightweight aggregates or super-absorbent polymers into concrete releases water, as the moisture surrounding the aggregates decreases. This process fills the unsaturated pores in the concrete and increases the meniscus radius of the pore solution, thereby achieving internal curing. Internal curing promotes cement hydration around the aggregates, improves the compactness of the interfacial transition zone, alleviates concrete cracking caused by self-desiccation, and enhances cracking resistance. Moreover, it obstructs the transmission path of corrosive media, improves concrete permeability, and enhances corrosion resistance against ions, gases, and other corrosive agents. After water release, the internal curing materials create a substantial number of pores within the concrete. These pores aid in releasing the expansion pressure resulting from the freezing of the concrete pore solution, thereby improving frost resistance. Additionally, the pores of lightweight aggregates provide space for the deposition of expansive gel, thereby reducing the occurrence of alkali-aggregate reaction.