With　the　rapid　development　of　modern　electronics,　the　next　generation　of　electromagnetic　interference　(EMI)　shielding　materials　requires　ultrathin,　lightweight,　flexibility　and　robustness　to　protect　electronic　devices　from　radiation　pollution.　In　this　study,　the　multifunctional　Ti3C2Tx/Bacterial　Cellulose　(Ti3C2Tx/BC)　composite　films　with　uniformly　lamellar　structures　have　been　developed　by　combining　experimental　and　theoretical　works.　The　microstructures,　mechanical　properties,　EMI　shielding　and　photothermal　conversion　performances　of　Ti3C2Tx/BC　composite　films　have　been　systematically　investigated.　It　is　highlighted　that　the　resultant　ultrathin　and　flexible　Ti3C2Tx/BC　composite　film　with　a　Ti3C2Tx　content　of　50　wt%　exhibits　satisfactory　tensile　strength　of　109.6　+/-　4.5　MPa,　excellent　electrical　conductivity　of　5020　S　m-1　and　EMI　SE　value　of　43.7　dB.　More　interestingly,　the　composite　film　displays　stable　and　fast-response　photothermal　characteristics,　with　the　photothermal　conversion　temperature　up　to　74.5　celcius.　This　study　proposes　a　versatile　strategy　to　synthesize　multifunctional　MXene/BC　composite　films　with　satisfactory　mechanical　properties,　high　performance　EMI　shielding　and　photothermal　conversion　effects,　which　shows　great　potential　for　the　protection　of　electronic　devices.