Clamping rods layout optimization method was investigated to solve wall thickness monitoring issue of wax pattern of gas turbine blade in this study. First, the resultant force and moment of ceramic core were obtained based on the simulation results of non-uniform pressure exerting on the ceramic core during injection process. Moreover, the ceramic core shifting with incompletely constrained of clamping rods was computed based rigid dynamic principle. Further, a clamping rods layout optimization model was established to control core shifting. An improved genetic algorithm was proposed to optimize the layout scheme for clamping rods. The experimental results indicated that the proposed method can minimize the shifting of ceramic core.