An enhancement of mid-wavelength infrared absorbance is achieved via a cost-effectively chemical method to bend the flakes by grafting two types of alkane octane （C₈H₁₈） and dodecane （C₁₂H₂₆） onto the surface terminals respectively. The chain-length of alkane exceeds the bond-length of surface functionalities T_x （=O，-OH，-F） so as to introduce intra-flake and inter-flake strains into Ti₃C₂T_x MXene. The electronic microscopy （TEM/AFM） shows obvious edge-fold and tensile/compressive deformation of flake. The alkane termination increases the intrinsic absorbance of Ti₃C₂T_x MXene from no more than 50% up to more than 99% in the mid-wavelength infrared region from 2.5 μm to 4.5 μm. Such an absorption enhancement attributes to the reduce of infrared reflectance of Ti₃C₂T_x MXene. The C-H bond skeleton vibration covers the aforementioned region and partially reduces the surface reflectance. Meanwhile， the flake deformation owing to edge-fold and tensile/compression increases the specific surface area so as to increase the absorption as well. These results have applicable value in the area of mid-infrared camouflage.