Abstract: Based on the result of physics and pyrology design, the design of subcritical blanket fission fuel zone structure is given for the fusion-fission hybrid reactor. This scheme includes longitudinal bone support structure, fuel zone structure and zirconium cladding structure. Using Pro/e CAD software, the subcritical blanket fuel zone structure model is established, at the same time, the preliminary mechanical analysis for the longitudinal bone style support structure is carried out by ANSYS-workbench mechanical finite software. Accordingly, the maximal Tresca stress value, the stress distribution contours and the total deformation are obtained, the maximal stress and deformation are respectively 87.04 MPa and 0.17 mm. In the light of the third strength theory, the above calculation results show that the longitudinal bone style subcritical blanket fuel zone structure can satisfy the strength requirements.