Abstract: In this paper, a method for optimizing the compaction quality control index of dam is proposed. Using the collected soil dry density samples, the statistics (mean, standard deviation and correlation distance) are determined. According to the correlation between deformation parameters and soil dry density, the random fields of material parameters are established, and the random finite element analysis is carried out to predict the dam structural responses and safety. Based on the quadratic polynomial, the response surface equation of statistics of soil dry density and dam response is established, and the exceeding probability expression is derived. In order to improve dam safety, soil dry density statistics are further optimized, which provides guidance for the adjustment of construction parameters. Through a practical project, the influence law of material uncertainty is studied in different filling stages. The uncertain deformation response analysis tends to be stable. The statistics of core-wall material have a great effect on maximum settlement and deformation gradient. By adjusting the exceeding probability, the statistics of soil dry density in each partition can be obtained, so as to guide the dam construction and improve the control level of dam deformation as well as safety evaluation accuracy.