The invention discloses a connecting component with the negative Poisson ratio effect and a design method thereof. The key point of the connecting component with the negative Poisson ratio effect liesin that the periphery of the connecting component is wrapped by a tubular structure outer tube, and two annular structures and an inner cylinder are connected with the outer tube. The outer tube andthe inner cylinder of the connecting component are fixed to two parts needing to be connected correspondingly, pressure is applied to the two annular structures on the outer tube of the connecting component, and the outer tube can shrink inwards; the friction force generated between the inner wall of the outer tube and the surface of the inner cylinder is increased, and thus, the outer tube is fixedly connected with the inner cylinder; otherwise, pull force is applied to the two annular structures on the outer tube of the connecting component, the outer tube expand outwards, and the outer tubeis separated from the inner cylinder. The connecting component is quite novel and can be applied to multiple occasions such as pen caps, cup lids and two ends of ropes and the like, and the quite high commercial value is achieved.