The invention relates to a radioactive decontamination process for martensitic stainless steel. The process comprises the following steps: (1) soaking a radioactive contaminated component by using oxidizing solution; (2) soaking the oxidized radioactive contaminated component by using deionized water; (3) soaking the radioactive contaminated component by using reducing solution; and (4) soaking the reduced radioactive contaminated component by using the deionized water. In the decontamination process, the reaction temperature is between 62 and 68 DEG C; the reducing solution used in the step (3) is mixed solution of oxalic acid and citric acid, and then, an alkaline reagent, namely solution of sodium hydroxide is added into the mixed solution; and pH value of the solution is adjusted to be between 4.2 and 4.5, and the solution is mixed uniformly, wherein the mass percentage of the oxalic acid is between 0.2 and 0.4 percent, the mass percentage of the citric acid is between 0.2 and 0.4 percent, and the mass percentage of the solution of sodium hydroxide is between 0.2 and 0.4 percent. The process greatly reduces the degree of radioactive decontamination of the martensitic stainless steel component, ensures the component can be used repeatedly, ensures body health of related staff, and effective reduces generation of radioactive waste.