S115 mineral powder was used as an admixture to prepare high-performance concrete modified with mineral powder. The effects of mineral powder substitution rate on the lattice structure, microstructure, mechanical properties and durability of concrete were analyzed through XRD, SEM and composite salt solution dry wet cycle testing. The results showed that the addition of an appropriate amount of mineral powder could accelerate the hydration reaction rate of cement and increase the density of the grid structure, thereby improving the microstructure of concrete and enhancing its strength. An increase in the replacement rate of mineral powder would reduce the early strength of cement paste and significantly improve the later strength of cement paste. When the replacement rate of mineral powder was 50%, the compressive strength and flexural strength of the concrete cured for 28 d reached their maximum values of 52.5 and 7.4 MPa, respectively. After replacing cement with mineral powder, the decline trend of relative dynamic elastic modulus and mass loss rate of concrete under the erosion of composite salt solution became gentle. After 30 dry wet cycles, the relative dynamic elastic modulus of concrete with a 50% mineral powder replacement rate was the highest at 88%, and the mass loss rate was the lowest at 1.6%, indicating the best resistance to salt solution erosion. The corrosion products of concrete are mainly needle like ettringite and block like gypsum. These products exist in the pores and cracks of concrete. After repeated drying and wetting cycles, the volume expansion produces internal stress, generates deep cracks and finally cracks the concrete, making the concrete invalid. Overall, the optimal replacement rate of mineral powder is 50%. [ABSTRACT FROM AUTHOR]