With the further intensification of globalization, research on the image of source countries has become a hot topic in the field of international marketing. This article starts with the concepts of source country, source country image, and source country effect, and reviews relevant literature on source country theory. It focuses on analyzing the verification, influencing factors, and mechanisms of source country image effect, and points out that there are still many shortcomings in the research and application of source country theory in international operations, such as strengthening relevant research on developing countries, paying attention to the source country effect of Chinese manufacturing in the international market, and strengthening applied research.