Based on a corpus of two translation versions of the three key documents released at the third plenary session of the 18th central committee of the CPC (the Communist Party of China), this article conducts a comparative study of the styles of the official translators and an independent overseas translator through the analysis of translation shifts as well as the linguistic features of the translated texts. It is found that the independent overseas translator is obsessed with formal correspondence, and his translation is characterized by long sentences, numerous Chinglish expressions and poor readability. By contrast, the official translators adopting a more flexible approach frequently opt for formal translation shifts (esp. addition and omission) so that their translation is more explicit and concise with fewer Chinglish expressions and better readability. Comparatively speaking, the official translation is more compatible with the linguistic habits of the target English readers and can more accurately convey the political and cultural messages in the Chinese political texts. Drawing on the interviews with an institutional insider of the official translation team and the independent overseas translator himself, we argue that these differences in translation styles can be attributed to their differences in translation skypos, translation procedure, and the linguistic background of the translator(s).