Based on comparing with the existing parallel algorithms for mining association rules, the paper analyzes CD,FDM,DDM algorithm in details. To overcome problems existing in efficiency of candidate sets pruning and execution time of these algorithms, the paper proposes parallel process algorithm with an improved parallel association rules. Finally the result of test on share-nothing cluster of workstation show that after adopting the improved algorithm, execution performance and efficiency are higher than others. This result indicates that the algorithm has achieved algorithm optimization.