This paper proposes a key-word query approach basing on relational database text field

aiming to search the expected result despite the wrongly input key words.The solution is to match the wrongly input key word and the"hot word "by setting up a" hot word database"to improve the dynamic programming algorithim in K-difference approximately string matching

so as to realize the relational databases error correction query.Experimental results show that this approach can achieve good retrieval performance.