Although humidity-responsive actuators serve as promising candidate in smart wearables, artificial muscles and biomimetic devices, most of them derived from synthetic polymer could not simultaneously achieve multifunctional properties. In this work, the cellulose nanofibers (CNF) based film actuator with high mechanical properties, excellent Joule heating and antibacterial capability are successfully constructed by integrating with Ti3C2Tx (MXene) and tannic acid (TA) via vacuum assisted filtration approach. Owing to the unique nacre-like structure and strong hydrogen bonds, the tensile strength and toughness of the composite film could reach 275.4 MPa and 10.2 MJ∙m-3, respectively. Importantly, the hydrophilic nature of CNF and alterable interlayer spacing of MXene nanosheets endow composite film with sensitive humidity response and extraordinary stability (1000 cycles). With the assistance of MXene nanosheets and TA, the composite film could not only present outstanding Joule heating, but possess remarkable antibacterial properties against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Benefiting from the above merits, the proof-of-concept smart garment is assembled by the as-prepared film and capable of regulating humidity and temperature.