Abstract: The mechanical modeling is established for the 3-D braided composite structures with embedded optical fiber sensors, the braiding process technique and trend of the fibers are introduced first of all, the interior cell model containing optical fiber section of the braided composite structure and the geometry relationship between the optical fiber and the fiber bundles or interior cells subsequently are setup,also a construction of the stress-strain relationship and state formula with the multi finite element variation method are presented. The consistency between the rational simulation and the test results systematically verifies the feasibility of optical fiber braided in the 3-D braided composites so as to improve detecting method effectiveness on dealing with the internal parameters.