The inclination of diplomatic discourse is an important element to measure the diplomatic games among big powers. The concept of diplomatic discourse inclination and relative calculation method are proposed from the perspective of cross-lingual set of word embedding in this paper. Based on the Chinese-English bilingual corpus of Chinese and American diplomatic spokespersons, the parameters are optimized by searching positive and negative keywords in Chinese, and English positive and negative sets of word embedding are further retrieved. The data references for the expression and translation of diplomatic discourses are provided by quantifying the diplomatic discourse inclination of both sides. The research results indicate that both China and the United States exhibit a positive discourse inclination, with China’s positive intensity significantly surpassing that of the United States. However, in the English translation of Chinese discourse, the proportion of China’s positive discourse is less than that of the United States, while the degree of negative reinforcement is greater than that of the United States. The findings suggest that in the game of diplomatic discourse, in order to construct an equivalent diplomatic discourse and political status with the United States, and better achieve diplomatic purpose with Chinese characteristics, as a dominant nation, China could increase the number of positive words and reduce the proportion of negative words in the English set of word embedding in translating from Chinese into English, so as to build an equal diplomatic relationship between China and the United States with equal positive and negative diplomatic discourses.