The facile preparation of layered double hydroxides (LDHs)/MXene composite at room temperature is still challenging. Herein, we designed and developed a fast and room-temperature synthesis method to fabricate NiCo-LDH/Ti3C2Tx composites with sandwichlike layered structures via direct NaBH4 reduction. DFT calculations show that such layered composites can reduce the hydrogen desorption energy and increase the electrical conductivity, which is advantageous to improving electrochemical performance of supercapacitors. These superior features result in the prominent electrochemical performance of the fabricated NiCo-LDH/5-Ti3C2Tx composite electrode, including high specific capacitance (721.5 C/g at 1 A/g), outstanding rate capacity (about 85.2% from 1 to 10 A/g), and excellent stability (80.4% of capacitance retention after 5000 cycles at 5 A/g). This study provides a facile way to construct layered LDHs/MXene composites with exceptional electrochemical performance, which is expected to be suitable for various applications.