With thick translation as the theoretical perspective, Wing-tsit Chan’s and John Knoblock’s English translations of the Xunzi are taken as examples to compare and analyze the chief forms of thick translation in the translations of philosophical terms in the two versions, the types and functions of thick translation are summarized, and the reasons are explored. It is found that Chan focuses on making philosophical comparisons, presenting the overall context of Chinese philosophy, and reproducing the specificity and core ideas of philosophical terms with various thick translation methods within the main body of the text such as interlinear notes, footnotes and comments, while Knoblock employs a model of co-supplement of endnotes supplemented with prefaces inside and outside the text, to construct a thick context for Xunzi’s thought, so as to fully convey the connotation of philosophical terms and provide detailed reference for further studies of Xunzi.