Origami- and kirigami-inspired thick-panel deployable structures are wildly used in diverse engineering applications. It is important to study their motion behaviors to accomplish the deployment process. Several kinematic-based methods have been proposed to address this issue, and thick-panel kirigami belongs to one of them. However, the kinematic-based method does not include panel mass, applied force, and energy of system, which cannot reflect the actual movement. In this paper, we propose a dynamic model based on constrained multibody systems that can analyze the complete deployment process of thick-panel kirigami structures. Since the kirigami structure may have bifurcation behavior in the fully deployed configuration, contact-impact process and rebound motion are considered in this model. The versatility of the proposed method is verified through numerically computed kirigami cases with different symmetric characteristics. Physical prototypes and experiments are carried out, which successfully validate our model. The results indicate that the complete deployment process is complex when these nonlinear aspects are involved. Though this paper considers only kirigami structures, the findings can be developed in the other thick-panel origami and kirigami concepts of practical engineering applications in the future.