The panel data is projected to the time dimension discrete curves and the index dimension discrete curves. Then, based on the thinking of discrete curvature, the incidence coefficient formulas of the time dimension and index dimension are respectively constructed. The grey curvature incidence model is constructed. The properties of the model, e.g., normalization, symmetry, similarity and translation invariance, are also satisfied. Finally, the comparison to some existing models and an example are given to illustrate the rationality of the proposed model, and the results show that the proposed model can better reflect incidence degree of panel data.