The opening rate is an important structural parameter of the shield machine cutter, and its size is directly related to the interaction between the cutter and the excavation surface. By designing a 1∶10 model test, it realizes adjustable opening rate of cutter and real time weighing of residue, thus indirectly realizing the control of soil chamber fullness. The study analysis showed that under the condition that the actual rate of excavation is equal to the theoretical rate of excavation, increasing the rate of cutter opening can reduce the contact surface between the cutter surface and the excavation surface, thus reducing the cutter torque, showing a 10% increase in cutter opening rate and an approximate 5.8% reduction in cutter torque. At the same emergence rate, the opening rate of the cutter has no significant effect on the maximum settlement of the ground surface. The slag soil on the cutter gap can have the support effect on the excavation surface when the soil compartment is nearly full.