Abstract: The cutting torque is an important construction parameter during tunnelling process by use of shield machines. It not only determines the difficulty degree of construction but also influences other working parameters, such as thrust force, advancing speed, rotation speed and driving power. Based on the cutting mechanism of EPB shield machine, a new reasonable calculation model of cutting torque is presented by applying mathematical and mechanical theories, and its influence factors are then discussed. Subsequently, model experiments on the cutting torque during tunnel excavation with EPB shield machine under different conditions of buried depth, cutter head aperture ratio, rotation speed and advancing speed are carried out. The aforementioned theoretical studies are then verified, and satisfactory results are achieved.