Rockfill belongs to the “special molecule” of the soil-filling,it has a great influence on investment,design and construction of enginees projects。Fully understanding the “harmfulness”,economic、reasonable and targeted design and construction measures can achieve the effect of avoiding design change,saving time and controlling cost。Engineering investigation is the most important basic work,whether the data is accurate or not,It can directly lead to different results。Through the practical engineering experience,this paper analyzes the influence of the rockfill layer on the construction of the project,and clarifies that the engineering investigation work should not only meet the requirements of the relevant standards,but also should pay attention to the key points and adopt measures,which can be reference in engineering investigation,design and construction。