Physical simulation test device and method for karst underground water system

The invention provides a physical simulation test device and method for a karst underground water system. The device comprises a model pool boundary with an outdoor site scale; according to the karst water-containing medium formed by arranging the regular limestone blocks, gaps between the first limestone blocks form a preset fracture grid structure, holes are formed in at least part of the first limestone blocks and are communicated with one another to form a preset karst channel structure, and at least one large hole section used for simulating a karst cave is arranged in the middle of the channel structure; a plurality of water level observation pipes; and a rainfall simulation system. According to the physical simulation test device and method for the karst underground water system, an artificial fracture-pipeline-karst cave system physical model is provided, the scale and design of the physical model comprehensively consider the hydrogeological parameter scale effect, the heterogeneity of a karst water-c