Shunbei Oilfield contains four types of storage media（i.e.，caves，high-angle fractures，vugs，and rock matrix）.The vertical beads-on-string structure formed by caves and high-angle fractures in series is a common fracture-cavity connection pattern. During drilling，drilling break and mud loss are prone to occur. These complex geological and engineering factors make it difficult for traditional multiple media models to fit the measured well test data. This paper proposes a physical model with multiple cave regions and multiple fracture regions in connection in series to characterize the complex vertical beads-on-string structure. The cave regions only contain caves in which the fluids are assumed to obey free flow. The fracture regions contain high-angle fractures，vugs，and rock matrix in which the flow obeys Darcy’s law. On this basis，the paper constructs a well test model for the beads-on-string structure with a wellbore-cave connection，draws type curves，and conducts a parameter sensitivity analysis. The following results are obtained：the cave storage regime and linear flow regime are the typical flow stages of vertical beads-on-string structure；the caves and conventional multiple media can be distinguished by the slope of pressure derivative curves；the type curves under the influence of gravity show pressure response characteristics similar to a closed boundary，so the measures should be taken to reduce the influence of gravity for improving the development effect of the vertical beads-on-string structure. Finally，the proposed model is applied to interpret the representative wells in Shunbei Oilfield. Besides the conventional reservoir parameters，the parameters that cannot be interpreted by existing well test methods can also be obtained by inversion，such as equivalent cave radius and equivalent cave height.