The invention relates to a well testing interpretation model for analyzing a fracture-cave series mode double-hole composite reservoir, which comprises the following steps of: 1, establishing a corresponding physical model according to reservoir characteristics of a certain type of oil reservoir; 2, establishing a mathematical model, wherein the mathematical model is used for describing a physicalmodel; 3, solving the mathematical model to obtain a real space bottom hole pressure solution; and 4, drawing a real space well testing theoretical curve by utilizing a real space well bottom pressure solution, analyzing the well testing theoretical curve, performing curve fitting on theoretical pressure data and actually measured pressure recovery data to obtain a fitting result, and obtaining interpretation parameters which comprise fracture conductivity, fracture length, karst cave volume and karst cave storage capacity ratio. By solving the well testing mathematical model of the fracture-cavity series mode, the well bottom pressure solution of the fracture-cavity series mode is obtained, the typical well testing curve is drawn, the stratum parameters are obtained, the well testing interpretation method of the fracture-cavity series mode double-hole composite reservoir is determined, and the fracture-cavity type oil reservoir is accurately evaluated and effectively developed.