1. A non-transitory computer-readable medium on which is stored a computer program for detecting and correcting mismatched Chinese characters in a phrase, the computer program comprising computer instructions that when executed by a computing device performs the steps of: (S 1 ) inputting an input phrase; (S 2 ) a mismatched character detection module comparing the input phrase with Chinese phrases stored in a database; (S 3 ) in step (S 2 ), if there is an exact match, the mismatched character detection module determining the input phrase as constructed correctly; (S 4 ) in step (S 2 ), if there is no exact match and an edit distance is greater than two, the mismatched character detection module determining the input phrase as an unknown phrase; (S 5 ) in step (S 2 ), if there is no exact match, the edit distance is two and the phrase length is two, the mismatched character detection module determining the input phrase as an unknown phrase; (S 6 ) in step (S 2 ), if there is no exact match, the edit distance is one, or the edit distance is two and the phrase length is greater than two, the mismatched character detection module looking up a database to retrieve the associated pronunciation and radical composition for each of the mismatched Chinese characters in the input phrase and sending the retrieved information to an mismatched character correction module; (S 7 ) the mismatched character correction module performing an adjacency match by swapping two adjacent and mismatched characters in the input phrase and see if the input phrase would match any of the partially matched phrases, if a match being found, the mismatched character correction module adding the partially matched phrase to a completely matched phrase list; (S 8 ) the mismatched character correction module comparing the pronunciation of the mismatched character(s) with that of the character(s) in the same position of the partially matched phrase, if the pronunciation is identical, the mismatched character correction module adding the partially matched phrase to the completely matched phrase list; (S 9 ) the mismatched character correction module comparing the pronunciation of the mismatched character(s) with that of the character(s) in the same position of the partially matched phrase, if the pronunciation is similar, the mismatched character correction module adding the partially matched phrase to the completely matched phrase list; (S 10 ) the mismatched character correction module compare the radical composition of the mismatched character(s) with that of the character(s) in the same position of the partially matched phrase, if there is a radical match, the mismatched character correction module adding the partially matched phrase to the completely matched phrase list.