Abstract: Aiming at the problem that the strain field of 3D braided composite is not uniform when it is loaded, the strain data of a small area on the surface of the sample cannot truly reflect the overall deformation of the material. In this paper, the strain measurement results of three different wire grid strain gauges, extensometers and non-contact 3D full-field strain measurement systems are compared and analyzed by the warp unnotched tensile test. The research results show that the strain field distribution of 3D braided composite is non-uniform under load, and the deformation amount varies greatly. The usage of strain gauge with a larger wire grid size can reduce the influence of non-uniform deformation of 3D braided composite, and obtain more accurate results. The non-contact 3D full-field strain measurement can accurately reflect the full-field strain of the tested sample, and provide accurate strain data for the mechanical property test of 3D braided composites.