Abstract: In order to study the dynamic compressive mechanical properties of ultra-high toughness cementitious composites (UHTCC) in coastal salt spray environment, dynamic compressive mechanical tests of three groups of different strain rates (10⁻⁴ s⁻¹, 10⁻³ s⁻¹, and 10⁻² s⁻¹) were carried out on two groups of ultra-high toughness cementitious composites with different corrosion degrees (corrosion period of 0 d and 60 d), and the dynamic compressive stress-strain curves and failure morphology of materials were obtained. The effect of strain rate on elastic modulus, peak strength and peak strain of ultra-high toughness cementitious composites with different corrosion degree was analyzed. The results show that the dynamic compressive strength of ultra-high toughness cementitious composites is 44.5%, 54.4% and 62.4% higher than that of the uncorroded specimen, and the dynamic elastic modulus is 19.4%, 15.3% and 28.4% higher than that of the uncorroded specimen; while the strain rate sensitivity of the compressive strength increases. X-ray computed tomography showed that the porosity of the material decreased and became denser.