A compound PIS (CPIS) method is first proposed in this article to further improve the efficiency of the path integral solution method, and the accuracy and efficiency of the CPIS method is validated.

• 为进一步提高路径积分法的效率，本文首先提出了一种复合路径积分法，而且这种复合路径积分法的精度和效率得到了证实。