In order to reduce the risk of mud cake formation in large-diameter slurry shield tunneling cutterheads in high clay mineral formations, a three-dimensional numerical model of the shield cutterhead and scouring system is established using numerical simulation methods based on actual engineering. The distribution characteristics of the flow field near the cutterhead were studied, and the angle of the central scouring hole was optimized under multiple working conditions. The results show that: The overall mud flow rate in the center area of the static region ② was higher than that in the outer area. However, there is a significant decrease in the mud flow rate in some parts of the central area, and there is still a risk of the debris from the cutting tools gathering again on the back panel of the cutter head, forming large mud cakes that can block the cutter head; When the scouring angles of the central scouring holes ② and ③ are arranged at 45°, the scouring effect on the outer area is more thorough, and when they are arranged at 90°, the scouring effect on the outer area is the worst; According to the streamline performance factors of the four working conditions in the stationary region ②, rotating region, and stationary region ①, the priority order of erosion angle design can be determined as follows: working condition 2>working condition 3>working condition 1>working condition 4, that is, the order of erosion hole brushing angle is 45°>70°>20°>90°, the research results can serve as a theoretical basis for optimizing the design of the cutter head erosion system.