Flexible and wearable electromagnetic interference (EMI) shielding material is one of the current research focuses in the field of EMI shielding. In this work, for the first time, WS₂-carbon fiber (WS₂-CF) composites are synthesized by implanting WS₂, which has a multiphase structure and a large number of defects, onto the surface of carbon fiber (CF) by using a simple one-step hydrothermal method, and are applied to protect electronic devices from EMI. It is found that the EMI shielding performance of WS₂-CF is significantly improved, especially for those at S— and C-bands. At 2 GHz, the EMI shielding efficiency could reach 36.0 dB at a typical thickness of 3.00 mm of the composite, which is much better than that of pure CF (25.5 dB). Besides paving a novel avenue to optimize the electromagnetic shielding performance of flexible and wearable CF-based EMI shielding materials, which have great potential in the practical application for EMI shielding, this work provides a new paradigm for the design and synthesis of EMI shielding materials which have a broad application prospect.