Abstract: Dagu Hydropower Station is located in the high altitude area with complex climate environment. Temperature control and crack prevention during construction are the key technical problems in the design and construction of the project. In this paper,5# slope dam section is selected as the research object to simulate the whole process of dam pouring. Considering the concrete creep,the three-dimensional finite element method is used for numerical simulation calculation. The temperature field and stress characteristics of the dam are studied,and the temperature control and crack prevention measures are proposed. The research results show that RCC dam construction in the high altitude area has the characteristics of high risk of cracking on upstream and downstream dam surface when concrete is poured in low temperature seasons and high risk of cracking in internal concrete when concrete is poured in high temperature seasons. After adopting the temperature control and crack prevention measures proposed in this paper,the temperature variation of upstream and downstream dam surface and warehouse surface is significantly reduced under the combined action of external temperature maintenance and internal water cooling. The anticrack safety degree of concrete on the surface and inside of the dam body can reach 1.8,which meets the engineering design requirements.