Abstract: With the continuous exploitation of marine resources, the preparation of in-situ all-coral concrete on islands and reefs has become a key technology for the construction and protection of island projects. In order to investigate the effect of different organic non-metallic fiber admixture on the mechanical properties of all-coral concrete, the dynamic mechanical properties were investigated by using the Split Hopkinson Pressure bar (SHPB) test and the impact process was numerically simulated by LS-DYNA. The results show that the static compressive strength of all-coral concrete can reach 113 MPa when the organic fiber mass percent is 1.2wt%, which is an increase of about 7.5% compared with the coral concrete without fiber dosing. Under the dynamic test, the dynamic compressive strength can reach 247 MPa at a strain rate of 120 s⁻¹, which is about 32.6% higher than that of the specimens without fiber admixture. The toughness index of all-coral concrete also increases with the increase of organic fiber admixture. In addition, the integrity of coral concrete specimens increases under the same impact conditions with the increase of organic fiber admixture. The error between dynamic strength test values and simulated values is 7% to be within the allowable error.