Abstract: The safety of high-core rockfill dams has sparked widespread concern due to their complex environments,large loads and high stress levels. However,crest cracking occurs frequently in practical engineering,which affects the anti-seepage and stability of dams,and it is of great significance to analyze and study the relevant factors affecting the dam crest cracking for the design and operation of dams. Based on this,by comparing the variation law of deformation gradient of dam crests before and after the cracking of typical dams,the deformation gradient is introduced as an index to analyze the influencing factors of dam crest cracking of high-core rockfill dams. Based on the relevant information of several built high-core rockfill dams,a research scheme considering the size of the dam body,the thickness of the overburden,the height and rate of water storage,and operation time is constructed. The results show that the deformation gradient of dam crest increases significantly with the increase in dam height,and the relationship between them is nonlinear. The dam crest cracking risk of high-core rockfill dams built on deep overburden is greater,but when the overburden thickness reaches more than 100 m,the deformation gradient of dam crests tends to converge. The deformation gradient of dam crests is more sensitive to high water storage level,and the deformation gradient of dam crest increases with the acceleration of water storage rate.