<p>Ti₃C₂T_x MXene exhibits promising potential as an energy storage material. However, a challenge arises from the tendency of two-dimensional MXene materials to stack, which adversely affects energy density and restricts the application scope of MXene-based supercapacitors. In this study, we propose a straightforward and reliable approach to fabricate three-dimensional porous MXene-RGO structures at room temperature. This method adopts a self-assembly strategy, uses magnesium powder as an in-situ sacrificial template, and then prepares Mg-Ti₃C₂T_x-RGO composite aerogel with a three-dimensional porous structure through freeze-drying. This three-dimensional porous structure can effectively suppress the interlayer stacking of MXene, thereby exposing more active sites. Meanwhile, the existence of the three-dimensional porous structure can also promote ion transport within the electrode material. Therefore, the Mg-Ti₃C₂T_x-RGO electrode has excellent electrochemical performance, achieving a specific capacitance of 333.6 F g⁻¹ at 2 mV s⁻¹ and retaining 74.9% of its capacitance at 1 V s⁻¹, along with remarkable cycle stability, maintaining 95.43% of its capacitance after 5000 cycles. Furthermore, the assembled Mg-Ti₃C₂T_x-RGO/carbon cloth symmetric supercapacitor demonstrates an energy density of 23.16 Wh kg⁻¹ at a power density of 166.81 W kg⁻¹, along with excellent cycle stability, retaining 84.37% of its capacitance after 5000 cycles. In summary, the three-dimensional porous MXene/RGO aerogel presented in this work features a simple preparation process and outstanding electrochemical properties, offering a novel reference for the development of high-rate supercapacitor electrode materials.</p>