A data cache method, device, and system in a multi-node system are provided. The method includes: dividing a cache area of a cache medium into multiple sub-areas, where each sub-area is corresponding to a node in the system; dividing each of the sub-areas into a thread cache area and a global cache area; when a process reads a file, detecting a read frequency of the file; when the read frequency of the file is greater than a first threshold and the size of the file does not exceed a second threshold, caching the file in the thread cache area; or when the read frequency of the file is greater than the first threshold and the size of the file exceeds the second threshold, caching the file in the global cache area. Thus overheads of remote access of a system are reduced, and I/O performance of the system is improved.