[PERSON] et al. [18] analyzed and explored the hydrochemical damage mechanism of sandstone through shear strength tests of sandstone under the action of different hydrochemical solutions. It was found that when the hydrochemical solution was more acidic or alkaline, the secondary porosity was larger, and the change of P-wave velocity was more significant. [PERSON] et al. [19] analyzed and compared sandstone specimens soaked in the NaOH solution for 28 days by using SEM electron microscopy scanning technique and X-ray powder crystal diffraction technique and established a convection-diffusion-reaction model of the water-rock system; the change in porosity was used to quantitatively describe the changes in the micro-structure of the rock due to water-rock action. [PERSON] et al. [20] obtained the creep equation of deep sandstone under chemical corrosion by a uniaxial creep test of sandstone under acidic and alkaline solution corrosion, and the corresponding model fitting curves and creep parameters were obtained by fitting the experimental data and verified its creep model. [PERSON] et al. [21] studied the evolution law of fracture opening in single-fissure granite under the condition of stress-chemical coupling and established the fracture opening evolution model under the permeation of alkaline solution and acidic solution, respectively. As for the dynamic mechanical tests, [PERSON] et al. [22] subjected the limestone specimens to corrosion in three groups of solutions with different pH (acid, neutral, and alkaline) and conducted the impact compression tests on them using the separated Hopkinson pressure bar apparatus and found that the porosity of the specimens increased gradually with the increase in corrosion time, and the dynamic compressive strength and dynamic elastic modulus of the limestone showed different degrees of deterioration after corrosion by different solutions, and the fractal dimension also increased. It can be seen that although there are more studies on the basic physical properties of rocks under the action of chemical corrosion at present, the research results were mainly focused on the static load test of rocks after acidic corrosion, while the dynamic load test of rocks after alkali corrosion was relatively little researched. In practical engineering, some underground projects are subjected to impact loads, such as rock burst and earthquakes, in addition to groundwater corrosion [23]; therefore, it is necessary to study the mechanical properties of rocks after the coupling effect of alkali chemical corrosion and dynamic mechanics. In order to study the effects of different corrosion times on the physical properties as well as dynamic mechanical properties of sandstone under a strong alkaline solution, sandstone specimens were subjected to the NaOH solution with pH 11 for corrosion (0, 1, 3, 7, 14, and 28 d), and then, the values of their basic physical properties were measured. The impact compression and Brazilian splitting tests were carried out on sandstone specimens after corrosion with alkaline solutions under the same loading conditions using a 50 mm diameter split Hopkinson pressure bar (SHPB) test apparatus. Due to the limitation of space, this paper focuses on the macroscopic mechanical parameters, such as dynamic compressive strength, dynamic stress-strain curve, dynamic elastic modulus, average strain rate, and dynamic peak strain of sandstone with corrosion time in the impact compression test.