Using a first principles methodology, the adhesion of tungsten carbide and ferritic steel is investigated to estimate the mechanism of cutting process, which facilitates cutting performance enhancement and working lifetimes elongating. The Fe (100)/WC (100) interface is adopted based on minimum mismatched lattices with aiming to provide the suitable models to explore the structural and electronic properties at the interface. The W- and C-terminated surfaces are employed to clear the features of different surfaces of tungsten carbide. The comparisons of DOS, including bulk WC, Fe and their low index surfaces, show that surface-induced feature is generally presented on the surfaces. Bond character at the interface is studied with difference charge density and electron localization function (ELF), which allow us to predict the interfacial strength. Adhesion is due to strong covalent Fe-C bonds at the C-terminated interfaces, while W-terminated interface has no enough evidence to verify the presentation of covalent bonds. The calculated results support some advanced atomic studies on complex interface structures, especially improving the surface quality of metal products after machining process.