As the advantage of composite materials of high strength, low weight ratio, widely used in the field of aerospace. The static mechanical experiments of 3D braided composites with different braiding angles and different thicknesses are carried out to study the effects of different weaving angles and thicknesses on the microstructure, mechanical properties and failure modes of the materials.Due to the anisotropy of 3D braided composites and their in-plane properties were tested, the axial tensile test and the transverse tensile test were carried out respectively ,from the test the static elastic modulus, Poisson's ratio, shear modulus and strength are obtained.