Abstract: In order to study the synergetic effect of He/H ion in ODS steel, single and co-irradiation experiments of ODS steel were carried out at room temperature, and the effect of irradiation damage on micro hardness of ODS steel was investigated. The experimental results show that He/H ion is mainly distributed around damage peak, H ion irradiation has greater influence on the micro hardness than that of He ion, the introduction of H ion causes the disappearance of He ion low temperature desorption peak, the fluence of He ion reduced by half makes the initial desorption temperature rise, and the micro hardness and positron lifetime results can be mainly ascribed to the difference of He and H ion interaction with defects.