Based on the legitimacy theory, A-share-listed companies in the Shanghai and Shenzhen Stock Exchanges from 2007 to 2018 are taken as the research sample. This paper explores the internal mechanism of how internationalization degree affects the greenwashing behavior of Chinese multinational enterprises, and tests the moderating mechanism of legitimacy pressures from the home country. The findings are as follows: First, under the background of internationalization, enterprises are more inclined to greenwash, and this tendency is more obvious with the increase in internationalization degree. Second, in the full sample analysis, the moderating effects of environmental regulation, public pressure, and industry pressure are not statistically significant. Third, the moderating effect of legitimacy pressures varies due to the heterogeneity of regions and property rights of the enterprises. The statistical significance of the moderating effect is affected by the diversity of environmental regulation measures, but it can be roughly concluded that the eastern and western regions show a negative moderating effect, and the central region shows a positive moderating effect. The current moderating effect of public pressure is much stronger than the lagging moderating effect, and it shows obvious regional and property rights differences. The moderating effect of industry pressure also shows obvious regional and property rights differences.