Provided in the present invention are a K-Truss graph-based storage system cache prefetching method, a system, and a medium, where method steps of the present invention include: when a data request stream in a system arrives, an access mode of the data request stream is determined; if said mode is a sequence mode, then n sequence blocks after a data block corresponding to the data request stream are prefetched and serve as prefetch data; otherwise, the data block corresponding to the data request stream serves as a query vertex to query a K-Truss graph, a truss structure matching the query vertex is obtained, and data of a data block from within the truss structure is obtained and serves as prefetch data; the K-Truss graph is updated according to the data block corresponding to the data request stream; and lastly a prefetch data block is prefetched into a main memory.