Abstract: Good construction optimization techniques could shorten the construction period and make reasonable use of resources. For Qinghe Reservoir in Liaoning Province, we used P6 software to optimize construction process and resources of the dam based on network planning technique. The practical application problems of P6 software, such as project creation and its structure decomposition, work supplement and work time estimation, logical relationship establishment among the works, progress calculation, progress optimization, resources and loading analysis, resources balance, et al., are illustrated in detail. Through optimization, the project was completed 24 days ahead of schedule and construction resources staggering in construction were realized, achieving ideal optimization effect. It could provide reference for construction optimization of other water conservancy project.