Abstract: This article analyzes the Apriori algorithm, and points out the limitations that it requires many accesses in the large-scale database mining and its efficiency is low.Based on the strategy accessing to DB once, it designs Apriori_ADO algorithm based on the Apriori.This algorithm avoids cutting frequently.Experimental analysis shows that the new improved Apriori_ADO algorithm reduces the time and space, and improves the mining efficiency of association rules.Apriori_ADO algorithm has strong practicality;it has been used for supermarkets in customer consumer knowledge mining, and has achieved satisfying results.