Dragonfly has excellent flight performance and maneuverability due to the complex vein structure of the wing. In this research, nodus as an important structural element of the dragonfly wing is identified and confirmed through an experimental foldscope visualization approach. Three vein structures were fabricated as, open-nodus structure, closed-nodus structure (with a flex-limiter) and rigid wing. Nodus has a great influence on the flexibility of the wing structure. Moreover, the closed-nodus wing (with a flex-limiter) enables the vein structure to be flexible without losing the strength and rigidity of the joint.