Abstract: The phenomenon of "three excesses" in China's construction project cost has existed for a long time, which seriously puzzles the investment benefit management of construction projects. Strengthening project cost management is to reasonably determine and effectively control the project cost. Its purpose is not only to control the project investment within the scope of examination and approval, but also to rationally use manpower, material resources and financial resources to control the investment benefit of fixed assets. In the past, the focus of project cost control has always been on the implementation stage of the project, but practice has proved that the influence of different stages of project construction on investment is very different. According to statistics, the cost control in the design stage has the greatest impact on investment. Abstract: Engineering design directly determines the scale and investment of the project. Hydropower engineering design mainly includes feasibility study, bidding design and construction drawing design. The workload of these three stages is generally 6: 1: 3, which only accounts for about 1% of the total project investment, but the impact degree is as high as 95%. Therefore, it is very important to control the project cost in the design stage of the construction project. At present, there are still some problems in the cost control of design stage in China, which need to be improved urgently after China's entry into WTO. The key is to implement quota design, clarify responsibilities, implement design bidding and introduce competition mechanism; Strengthen quality control, improve the design level, and control the project cost reasonably. -Thank you for your graduation thesis. Author: Thank you for this research and bachelor of arts thesis for a month, which was completed under the cordial care and careful guidance of my tutor, Associate Professor Yin Yanyan. I have always admired and admired her approachable and amiable teachers and students. Her meticulous, eclectic, rigorous and meticulous, serious and responsible guiding style is an example for me to learn; Her serious scientific attitude, rigorous academic spirit and work style of striving for perfection deeply infected and inspired me and gave me endless enlightenment and lifelong benefits. From the beginning of the project to the final completion of the paper, Mr. Yin always gave me careful guidance and unremitting support. I would like to extend my highest respect and heartfelt thanks to Teacher Yin! When the paper is about to be completed, my heart is surging and my mood will never be calm. How many respectable teachers, classmates and friends have given me wordless help from the beginning to the successful completion of the thesis defense and finalization? Please accept my most sincere thanks! Finally, I want to thank my thrifty parents who trained me from primary school to university. Thank you! Although my family is very poor, you always give me the greatest understanding and financial support on my way to school. It was your support and understanding that got me into a school and read a lot of books. Only then did I complete this insignificant and painstaking work and fill a small gap in the history of literature. I sincerely thank you for publishing your first paper on the study of Lei Pingyang's poetry. My dearest parents!