The triaxial woven fabric is known for their light weight and isotropy of mechanical properties. However, researches that using it as reinforcement to form different structural composites were rarely mentioned. Here, we found that the effect of the triaxial woven fabric can be almost equivalent to the unidirectional fabric in flexural strength (99.18%) when it was added as a reinforcing material into the unidirectional fabric composites even though the weight of triaxial woven fabric has only a third of unidirectional fabric. Moreover, the effects and mechanisms are quite different when changing the position of the triaxial woven fabric in the composites. The damage modes of composites when triaxial woven fabric in different stacking sequences were summarized and the resin blocks model from triaxial woven fabric composites was presented in this paper.