The invention discloses an X ray target assembly for an SEM, and relates to the technical field of SEMs. Secondary electrons generated after bombardment of an SEM electron beam on a target material can be shielded effectively, and the problem that the secondary electrons and stray light induced by the secondary electrons cause adverse influence on the imaging quality of X rays is solved. The X raytarget assembly for the SEM comprises a target material and a shielding case, the target material is disposed in the shielding case, the shielding case is provided with at least one incident port andat least one exit port, one or multiple target material(s) is/are disposed in the shielding case, and each target material is provided with the corresponding incident port and exit port in the shielding case. The electron beam of the SEM is input via the incident ports, X rays generated after bombardment of the target materials are output via the exit ports, secondary electrons generated by bombardment are shielded effectively by the shielding case, and influence of secondary electrons and stray light induced by the secondary electrons on the imaging quality of X rays is avoided.