The chemical short-range ordered structure in multi-principal element alloys has been regarded as an effective strengthening method. It also can affect the distribution of elements at grain boundaries. In order to study the effect on the properties of Al0.5CoCrFeNi alloy, the effects of chemical short-range order at several typical grain boundaries on the tensile and radiation resistance of Al0.5CocrfenI alloy were studied by molecular dynamics method. The relevant influence mechanism is explained by dislocation analysis and point defect analysis. The results show that the segregation of elements at grain boundaries is more obvious with higher mismatch degree. Chemical short-range ordering can improve the tensile properties and radiation resistance of bicrystals, especially for bicrystals with large mismatched grain boundaries, which can effectively absorb radiation and produce interstitial atoms.