In order to speed up the progress of the concrete dam construction, the concrete thick layers and short time intervals fast pouring method is proposed. The temperature cracking and stress safety of the dam under concrete fast pouring method is a big trouble. From the concrete cracking safety point of view, a concrete gravity dam is introduced as a case study, the influence of different thickness of layers, different time intervals and different pouring temperature on the temperature and thermal stress characteristics of the concrete dam at the early age as well as the cracking risk of the concrete are deeply studied. According to the analysis, the corresponding cracking prevention technology is put forward. The research provides a technical support for establishing the concrete temperature control criteria and the relevant temperature control measures for the concrete fast pouring method.