The silicon carbide (SiC) epitaxial growth process is crucial in chip manufacturing. The growth rate and uniformity of epitaxial film are two critical evaluation criteria of epitaxial process. In order to obtain a higher growth rate and more uniform epitaxial film, it is necessary to improve the SiC epitaxial growth process. The traditional method to improve the epitaxial growth process is the “trial and error method”, but this method will consume a lot of time and economic costs. Therefore, it is necessary to find an efficient way to simulate the epitaxial growth process of SiC. This work uses computer aided Multiphysics simulation method to study the growth of SiC epitaxial films in a horizontal hot-wall chemical vapor deposition (CVD) reaction chamber. Firstly, a three-dimensional model of a horizontal hot-wall CVD reaction chamber is established, in which the MTS (methyltrichlorosilane)/H2 is used to deposit SiC epitaxial films on large-area substrates. The effects of temperature, gas flow distribution ratio, and pallet speed on the growth rate and uniformity of SiC epitaxial films are studied. The results show that: 1) In the range of 1500K-1600K, the higher temperature brings the higher growth rate of SiC epitaxial film. 2) The gas flow ratio of three groups of air inlets can simultaneously affect the growth rate and uniformity of the SiC epitaxial film. With the greater the airflow at the middle air inlet, the higher growth rate and the lower film uniformity will be obtained. 3) The tray rotation speed does not affect the film growth rate, but the higher of film uniformity will be achieved under the higher tray rotation speed. The simulation results agree well with the experimental results, which proves that the Multiphysics simulation method is feasible and can be used for further optimization of the epitaxial growth process of SiC.