Two different kinds of structural preforms were designed and manufactured, which were 3D layer-to-layer angle-interlock structure and 3D solid orthogonal panel structure. C/C composites were made first by chemical vapor infiltration (CVI) and then liquid resin impregnation for complementation. The bending properties of the two 3D woven reinforced C/C composites were tested and analyzed. The inner microstructures were investigated by SEM. The results show that the bending property of 3D solid orthogonal panel preform reinforced C/C composites is higher than that of 3D layer-to-layer angle-interlock preform reinforced C/C composites, and the bending rupture of the former is brittle, the latter is tough.