Background <p>Shear properties are critical to the structural integrity of carbon/carbon (C/C) composites. However, current testing methods primarily focus on quasi-static conditions, leading to a significant gap in understanding the differences in shear behavior under dynamic versus static loading.</p> Objective <p>This study aims to develop a novel shear testing method capable of accommodating both dynamic and static loading conditions, utilizing an improved V-notch beam (VNB) fixture integrated with a guide-slider system, and to investigate the shear behavior of three-dimensional woven C/C composites.</p> Methods <p>Shear tests were conducted using both a universal testing machine and a high-speed tensile testing system. Digital Image Correlation (DIC), combined with high-speed imaging, was employed to analyze strain distribution and capture the failure process during loading.</p> Results <p>The composites exhibited pronounced anisotropy in shear properties, with shear strength and modulus in the XY- direction significantly higher than in the Z-direction. Both properties were highly dependent on strain rate, increasing with higher applied strain rates. Failure modes varied with orientation: fiber pull-out, interfacial debonding, and matrix cracking predominated in the XY- direction, while interlaminar delamination was dominant in the Z-direction. Inertial effects further influenced failure modes under dynamic loading.</p> Conclusions <p>The newly developed VNB fixture significantly enhances the accuracy and reliability of shear testing for three-dimensionally woven C/C composites. The results highlight the anisotropic and strain-rate-sensitive shear behavior, which is closely linked to the material’s microstructure and failure mechanisms under different loading conditions.</p>