The invention provides an inner position loop impedance control algorithm for a mechanical arm with joint flexibility/arm lever flexibility, and belongs to the field of intelligent algorithm optimization; and motion simulation of contact operation of the two-connecting-rod flexible joint/flexible arm lever type mechanical arm is realized. The method comprises the steps of performing arm lever discrete analysis by utilizing an assumed mode method; building a mechanical arm dynamics model by adopting a Kane equation; designing an inner position loop impedance controller; and establishing a control simulation platform based on Simulink, thereby realizing the motion of the contact operation of the mechanical arm. A simulation result shows that the existence of a flexibility characteristic causes deformation of the arm lever; and the designed impedance controller can realize trajectory tracking and contact force control of the flexible mechanical arm.