Abstract: Inter-ply slipping is one of the important mechanisms in prepreg stacking preforming, and the research of inter-ply slipping mechanism can effectively predict and control the defects such as wrinkling and tearing, which is of great theoretical significance to improve the mechanical properties and service life of composites. At present, the research on inter-ply slipping mechanism mainly involves inter-ply slipping tests and the construction of inter-ply slipping models. The most commonly used test method is to conduct inter-ply slipping test using the homemade measuring device under different prepreg layups and process conditions. In terms of model construction, according to the characteristics of the inter-ply slipping model, the model can be classified into three categories: Early mixed models, phenomenological models based on Stribeck theory and empirical models. In this paper, firstly, the classification of inter-ply slipping devices is reviewed, and the advantages and disadvantages of each type of device are dissected. And then the research results such as the characterization of inter-ply slipping performance and the construction of models are introduced in detail. Finally, the development direction of inter-ply slipping in the resin-matrix composite forming is prospected.