The invention provides a 4H-SiC three-dimensional atomic structure model with a deflection angle of 8 degrees, a construction method therefor and an application thereof. The model is a periodically repeated structure of a 4H-SiC hexagonal crystal cell, and crystal cell parameters are as follows: a is equal to 3.08A+/-0.5%, b is equal to 3.08A+/-0.5%, c is equal to 10.06A+/-0.5%, alpha is 90 degrees, beta is 90 degrees, gamma is 120 degrees, the crystal cell is composed of a tetrahedron with a silicon atom in the center, the length of a carbon-silicon bond is 1.89A, and an upper surface edge (0001) of the model faces to <1120> and deflects by 8 degrees; the model is constructed in a computer-assisted mode, the method is simple and feasible in step, and the model is constructed completely with a silicon carbide surface treatment method in a practical production process; the 4H-SiC three-dimensional atomic structure model with the deflection angle of 8 degrees can be applied to research of a silicon carbide oxidation principle, silicon carbide ohmic contact and interfaces of silicon carbide materials, such as silicon carbide epitaxies and the like, and other materials; and compared with a commonly used deflection angle-free atomic model, the 4H-SiC three-dimensional atomic structure model with the deflection angle of 8 degrees is closer to practical application, a research result is closer to a practical situation, and a reference value is higher.