This study examined the process of oral translation from Chinese to Japanese for Chinese advanced level Japanese language learners by using a repetition task in Chinese and a Chinese-Japanese oral translation task. These tasks were manipulated to compare the reading time of isomorphic synonyms and homographs in sentences. The experimental results showed that isomorphic synonyms tended to have signifi cantly longer reading time than homographs in the Chinese-Japanese oral translation task. This result shows that when reading isomorphic synonyms in Chinese, the phonological representation of Japanese was also activated, which indicates the possibility of code-switching between the two languages. In addition, based on the translated texts provided by the participants in the Chinese-Japanese oral translation task, the reason for the mistranslation of homographs was analyzed from a word-linkage perspective. That is, homographs will be mistranslated if accurate vocabulary and semantic connections were not formed between the Chinese and Japanese languages. A Chinese-Japanese oral translation model was proposed based on the results of online processing of isomorphic synonyms and homographs, and the reason for the mistranslation of homographs.