1. A text conversion method for converting a paragraph in a source language into a target language, adapted to an electronic device having a processor, wherein the paragraph comprises a plurality of source language terms, the text conversion method comprising: providing a term mapping table by the processor, 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 by the processor to obtain a plurality of tokenization results; comparing the tokenization results with the term mapping table by the processor 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 by the processor according to the term mapping relationship recorded in the term mapping table; regarding each of the source language terms belonging to the second type, calculating a co-occurrence relevance of a plurality of relevant terms corresponding to each of the candidate target language terms by using a language model by the processor, 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; selecting a plurality of candidate language terms corresponding to higher ones of the co-occurrence relevance among the candidate target language terms by the processor, wherein each co-occurrence relevance corresponding to one of the selected candidate target language terms is higher than a first threshold; respectively translating each word in each of the selected candidate target language terms into a corresponding reference language word by using a dictionary supporting the target language and a reference language by the processor; determining a relevance between the corresponding reference language words in each of the selected candidate target language terms according to the dictionary and the corresponding reference language words by the processor, so as to select the candidate target language term having the highest relevance between the corresponding reference language words as the target language term; and converting the source language term into the target language term in the paragraph by the processor.