The SiGe thin films, such as hydrogenated amorphous SiGe (a-SiGe:H) and hydrogenated microcrystalline SiGe (μc-SiGe:H), are known as a potential material. In order to form promising SiGe thin films using chemical vapor deposition, relationship between materials/process and structure/composition should be clarified at the atomic level. We analyzed the influence of the substrate temperature and the ratio of SiH3 and GeH3, which are considered to be the dominant gaseous species on the deposition, on the crystallinity and atomic content in SiGe thin films by reactive force-field molecular dynamics simulations. The crystallinity increased as the substrate temperature increased, and the lowest crystallinity was obtained when the ratio of SiH3 and GeH3 is approximately 0.5. The hydrogen content decreased as the substrate temperature increased, while silicon and germanium content tended to increase as substrate temperature increased. These results were in good agreement with relevant studies.