As an economical and environmentally friendly dam construction material with high water-binder ratio and low cementitious material consumption,cementitious sand and gravel fill construction process is similar to that of concrete rolling construction.It has the characteristics of thicker single paving thickness and higher construction efficiency.This paper takes Wuyi Dam protection area of Longxikou Navigation-power Junction project as an example,studies the application of cementitious sand and gravel dam construction technology in the protection of super-long reservoir area,and analyzes two aspects of its mechanical properties and permeability to further expound the scientific application of cementitious sand and gravel dam construction technology in the safety protection of reservoir area.The results show that the cementitious sand and gravel dam construction technology has excellent stability and compressive resistance under the action of external forces such as water pressure in the reservoir area,and its tight structure and uniform material help to reduce the water penetration,thereby protecting the stability and safety of the reservoir interior.