A control method of a mechanical articulated arm, wherein at least two tilt sensors are arranged at different positions of the articulated arm, and the method includes: calibrating the zero positions of the tilt sensors when the articulated arm does not have elastic deformation, setting that the positions of the tail end of the articulated arm are respectively point P and point P' before and after the elastic deformation, and selecting a point R at the articulated arm, wherein the point R selected at the articulated arm is the middle position of the arc formed after the elastic deformation of the articulated arm; using the tilt sensors to detect the angle values of the two different positions of the articulated arm before and after the elastic deformation, wherein the position of the articulated arm before the elastic deformation is the zero position of the tilt sensors, said articulated arm being placed at a stand having a complete supporting structure, wherein elastic deformation of the articulated arm occurs during movement of the articulated arm, obtaining an angle offset Δ θ of the articulated arm due to the elastic deformation by setting the angle values detected by the tilt sensors at the head end and the tail end of the articulated arm before the elastic deformation as θ a 0 and θ b0, respectively, and setting an angle difference as Δ θ 0 rendered due to that the mounting positions of the tilt sensors are not parallel to the axial direction of the articulated arm, then: Δ θ 0 = θ b 0 − θ a 0; and setting the position of the head end of the articulated arm as point O, using the tilt sensors to respectively detect the angle values of point O and point P' which are represented by θ a 1 and θ b 1, respectively, then calculating the angle offset Δ θ as follows: Δ θ = θ b 1 − θ a 1 − Δ θ 0, and calculating a length parameter La and an angle parameter θa of the articulated arm after the deformation based on the angle offset Δ θ and the length values of OR and RP', wherein calculating the length parameter La and the angle parameter θ a of the articulated arm after the elastic deformation comprises the following steps: setting the angle values of ∠ROP' and ∠RP'O as ∠1 and ∠2, respectively, then: Δ θ = ∠ 1 + ∠ 2; according to the triangle theorem, the following is rendered: sin ∠ 1 | O R | = sin ∠ 2 | R P ' | = sin π − Δ θ | O P ' |; substituting the formula " Δ θ =∠1 + ∠2" to render: sin Δ θ − ∠ 2 = | O R | R P ' sin ∠ 2, thereby obtaining the angle θa and the length La of the articulated arm: { θ a = θ a 1 − ∠ 1 L a = | O P ' | = | R P ' | sinΔ θ sin ∠ 2.; and obtaining the position parameters X' p and Y' p of the point P' according to the length parameter La and the angle parameter θa, and controlling the action of the articulated arm according to the position parameters X' p and Y' p. calibrating the zero positions of the tilt sensors when the articulated arm does not have elastic deformation, setting that the positions of the tail end of the articulated arm are respectively point P and point P' before and after the elastic deformation, and selecting a point R at the articulated arm, wherein the point R selected at the articulated arm is the middle position of the arc formed after the elastic deformation of the articulated arm; using the tilt sensors to detect the angle values of the two different positions of the articulated arm before and after the elastic deformation, wherein the position of the articulated arm before the elastic deformation is the zero position of the tilt sensors, said articulated arm being placed at a stand having a complete supporting structure, wherein elastic deformation of the articulated arm occurs during movement of the articulated arm, obtaining an angle offset Δ θ of the articulated arm due to the elastic deformation by setting the angle values detected by the tilt sensors at the head end and the tail end of the articulated arm before the elastic deformation as θ a 0 and θ b0, respectively, and setting an angle difference as Δ θ 0 rendered due to that the mounting positions of the tilt sensors are not parallel to the axial direction of the articulated arm, then: Δ θ 0 = θ b 0 − θ a 0; and setting the position of the head end of the articulated arm as point O, using the tilt sensors to respectively detect the angle values of point O and point P' which are represented by θ a 1 and θ b 1, respectively, then calculating the angle offset Δ θ as follows: Δ θ = θ b 1 − θ a 1 − Δ θ 0, and calculating a length parameter La and an angle parameter θa of the articulated arm after the deformation based on the angle offset Δ θ and the length values of OR and RP', wherein calculating the length parameter La and the angle parameter θ a of the articulated arm after the elastic deformation comprises the following steps: setting the angle values of ∠ROP' and ∠RP'O as ∠1 and ∠2, respectively, then: Δ θ = ∠ 1 + ∠ 2; according to the triangle theorem, the following is rendered: sin ∠ 1 | O R | = sin ∠ 2 | R P ' | = sin π − Δ θ | O P ' |; substituting the formula " Δ θ =∠1 + ∠2" to render: sin Δ θ − ∠ 2 = | O R | R P ' sin ∠ 2, thereby obtaining the angle θa and the length La of the articulated arm: { θ a = θ a 1 − ∠ 1 L a = | O P ' | = | R P ' | sinΔ θ sin ∠ 2.; and obtaining the position parameters X' p and Y' p of the point P' according to the length parameter La and the angle parameter θa, and controlling the action of the articulated arm according to the position parameters X' p and Y' p.