1. A text conversion method for converting a paragraph in a source language into a target language, wherein the paragraph comprises a plurality of source language terms, the text conversion method comprising: providing a term mapping table, wherein the term mapping table records a term mapping relationship between the source language and the target language; performing a tokenization process on the paragraph to obtain a plurality of tokenization results; comparing the tokenization results with the term mapping table to determine that each of the source language terms is belonging to a first type or a second type, wherein each of the source language terms belonging to the first type is corresponding to a single target language term, and each of the source language terms belonging to the second type is corresponding to a plurality of candidate target language terms; converting the source language terms belonging to the first type into the corresponding target language terms according to the term mapping relationship recorded in the term mapping table; and regarding each of the source language terms belonging to the second type, selecting one of the corresponding candidate target language terms as the target language term of the source language term according to a co-occurrence relevance of a plurality of relevant terms, wherein each of the relevant terms is constituted by one of the candidate target language terms and at least one word before and after the candidate target language term in the paragraph.