This paper proposes method that utilize neural network model and retreival of index database that construct to character information of CAD drawing. Uses query extend method that proper combine of weight, index separation, entropy, collocation similarity to neural network model. This to retrieval other documents according to weight techniques with retrieval model treat to one query in index retrieval can retrieval suitability drawings effectively by combining multiplex evidences properly. Finally, apply artificial intelligence techniques to index retrieval system to evaluate efficiency of method that propose in this paper that see