Abstract: Aiming at the false negative problem and the overlap problem in pattern instance detection,in order to improve the accuracy of the design pattern recovery,this article introduces an approach for design pattern detection based on the formal context-free grammar relation driver. Focusing on the attribute and relationship of classes in pattern instances,the formal grammar of pattern instance identification is established using the visual language,and an improved formalism grammar is presented for identifying the additional relationships and the sharing problem of design pattern instances. Experimental results show that,compared with other wellknown algorithms by precision,recall and F-score,the proposed method can reduce the false negative results and the overlap problem in pattern instance detection,indicating the effectiveness of the proposed method.