A control method of a mechanical articulated arm, wherein at least two tilt sensors are arranged in different positions of the articulated arm, comprising: calibrating zero positions of tilt sensors when articulated arm does not have elastic deformation, setting position of tail end of articulated arm as point P and point P′ before and after elastic deformation of articulated arm, and selecting point R on the articulated arm; detecting angles of two different positions of the articulated arm with the tilt angles before and after the elastic deformation, obtaining the angle offset Δθ of the articulated arm due to the elastic deformation, and calculating the length parameter La and the angle parameter θa of the articulated arm after deformation based on the lengths of OR and RP′; and controlling the action of the articulated arm according to position parameters Xp′ and Yp′ (to the point P′) obtained according to length parameter La and angle parameter θa.