Abstract: The increasing popularity of 5G electronic consumer products has brought convenience to people’s life, while there are some problems, such as high risk of electromagnetic interference (EMI) and high power consuming of 5G networks. To solve these problems, it is necessary to develop novel materials with high EMI shielding performance and high-capacity electrode materials. As a new two-dimensional (2D) material, transition metal carbides/nitrides (MXene) have excellent conductivity, low density, hydrophilic surface, 2D layer morphology and tunable surface chemistry, etc. MXene shows promising application prospects in EMI shielding and energy storage due to the facile operation for fabricating films. A lot of MXene-based composite films have been reported recently. Thus in this article, we introduced the preparation methods of MXene nanosheets and MXene-based composite films including their advantages and disadvantages. Secondly, we summarized the research progress of MXene in lithium battery, supercapacitor and EMI shielding fields, and concluded the current mainstream composite materials and the characteristics of MXene composite film in structure and performance. Finally, we proposed critical insights on these scientific challenges and potential solutions. Besides, a future perspective on this technology including other challenges was also described.