The built-in limitations of the separate use of nano-SiO2 (NS) and layered double hydroxides (LDH) necessitate their combined use for improving the resistance of chloride transport into concrete. This study investigates the effect of a novel nano-SiO2@MgAl-LDH (NS@LDH) core–shell material (fabricated by in-situ co-precipitation method) on chloride transport of cement mortar through a comparative experiment. The mechanical properties, chloride-bound isotherms, rapid chloride migration (RCM), and chloride natural diffusion of mortar specimens were measured. The results show that the addition of NS@LDH improves both the compressive and flexural strength of mortar. Compared to mortars incorporating NS and LDH separately, the NS@LDH incorporated mortars exhibit a higher resistance to chloride transport. The chloride diffusion coefficient of the 2 % NS@LDH incorporated mortar is the lowest (reduced by 79 %). The NS@LDH induced combined effect of a significantly increased chloride-bound ability and refined microscopic structures contributes to the elevated resistance to chloride transport.