Abstract��Firstly, the improved method based on Java was introduced. A reasonable experimental threshold had been obtained, which improved the efficiency of quicksort when sorting a small dataset. Secondly, quicksort was optimized by using the multi-thread technology, and experiments were conducted to compare the performance of the single-thread and multi-thread algorithms. The results show that the multi-thread algorithm is several times faster than the single-thread one on multi-core computers. Finally, theoretical analysis was made on multi-thread quicksort algorithm, and the theoretical upper limit of the algorithm was obtained on multi-core computers.