Integrated design method and system for positive displacement motor and PDC drill bit

The invention discloses an integrated design method and system for a positive displacement motor and a PDC drill bit. The integrated design method comprises the steps that rock mechanical parameters of a target layer are obtained; establishing a three-dimensional cutting structure of the PDC drill bit; establishing a volumetric motor three-dimensional structure; calculating output parameters of the positive displacement motor according to the three-dimensional structure of the positive displacement motor; establishing a drill bit-rock finite element model considering the positive displacement motor; based on the drill bit-rock finite element model, a bit pressure torque time travel curve is obtained; and based on the bit pressure torque time travel curve, a positive displacement motor and PDC drill bit integrated design scheme is established. By the adoption of the technical scheme, the coupling influence mechanism of the cutting strategy, the number of the positive displacement motors and the pitch of the po