Abstract: Fractured-cavity carbonate reservoir represented by the Tahe oilfield in recent years in China is in the development of the large reservoir.The reservoir space types are mainly large caves, dissolved holes and multiscale fractures. Scale size disparity, irregular shape, and distribution are not continuous. Quantitative characterization of reservoir in 3D spatial distribution has been a technical problem, there is still lack of effective reservoir modeling method. In this paper, taking Tahe fractured-cavity carbonate reservoirs as the prototype,multiscale karst facies-controlling fractured-cavity carbonate reservoirs modeling method was studied and proposed. This method under control of the ancient karst development mode, according to the differences of measure, using two step modeling method: The first step is in the establishment of four discrete distribution models of a single type of reservoir, namely the use of seismic identification and description of the results, the establish certainty a large cave discrete distribution model and large-scale fracture discrete distribution model, in karst facies constraints, based on the probability of caves and fractures development body between the body and the wells, multi-attribute co-simulation, and the establishment of the dissolved holes stochastic model, and the small scale fractures discrete model; The second step is using parity conditions assignment algorithm, four single type of model integrae into multi-scale discrete fractured-cavity reservoir 3D distribution model. Quantitatively characterize the distribution characteristics of fractured-cavity reservoir in 3D space has laid a solid geological foundation for oilfield development.