Lightweight and integrated electronic devices require flexible polymer films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. MXenes (2D transition metal carbides or nitrides) attracted increased interest due to its layered structure and tunable surface chemistry. Few research has been published on the use of MXenes as fillers to improve the characteristics of polymers. Herein, Ti3C2TxMXene/Polyimide composite film was synthesized that exhibit enhanced thermal conductivity and excellent EMI shielding values with good flexibility and flame retardancy. Hence, the MXene/PI composite film with good flexibility, flame-retardancy, high mechanical strength and efficient heat transmission, imply promising perspective in next generation electronics and smart devices.