Creating composite materials that excel in both electromagnetic shielding performance and mechanical properties is a notable challenge in materials science. In this work, we present an effective strategy to enhance the electromagnetic interference (EMI) shielding performance and interfacial properties of carbon fiber-reinforced poly(arylene sulfide sulfone) composites (CF/PASS) by integrating a three-dimensional (3D) MXene-reinforced cross-linked network. This 3D MXene-reinforced cross-linked network not only establishes a strong physical and chemical bond between carbon fibers and the matrix resin but also forms an enhanced conductive network with carbon fiber during the bonding process with PASS resin. Assessments of EMI shielding performance and mechanical property reveal that applying a coating of HS-PASS with 1 mg/mL MXene to the CFs substantially improves the EMI shielding performance and mechanical property of CF/PASS composites. Specifically, the CF@HS-1MXene/PASS composite experiences significant increases in interfacial shear strength (IFSS), interlaminar shear strength (ILSS), and tensile strength by 59.2, 109.1, and 23.7%, respectively. Moreover, the CF@HS-1MXene/PASS composite capitalizes on the network structure of the CFs and MXene to facilitate multiple interfacial polarizations and conductive losses. This strategic configuration enables the composite to achieve an effective EMI shielding performance of 22 dB within 8.2-12.4 GHz. This performance is significantly enhanced relative to that of the desized CF. The synergistic enhancement of the mechanical property and EMI shielding performance not only broadens the applicability of CF/PASS composites but also pioneers new avenues for interfacial modification in composite material technology.