Synonym expansion based relational database keyword search method

The invention provides a synonym expansion based relational database keyword search method. The method successively includes the following steps: establishing a synonym database; sorting a plurality of words according to synonym and storing the words to the synonym database, wherein the synonym database includes groups of synonym word groups K, each synonym word group consists of a plurality of synonyms (k1, k2, ..., kn), and during search, a user gives a keyword group X, and the keyword group X consists of a plurality of keywords (x1, x2, ..., xn ); inputting keywords into the synonym database, and matching the keywords and words in the synonym database, wherein if one keyword is matched with a certain word in the synonym database, the synonym word group where the word is located is the synonym of the keyword. Through the query expansion method based on the synonym database, the keyword search technique and characters of all the fields are integrated, a keyword search system which is applied to different fie