Disclosed herein are a method and system for supporting user-level DMA I/O in a distributed file system environment. The system includes a DMA I/O library located in a user space and configured to process data-processing requests of an application using a control channel or a data channel, a distributed file system client process located in the user space and configured to process data while communicating with a remote distributed storage cluster, a VFS located in a kernel space, and a FUSE kernel module located in the kernel space, wherein the control channel is a path along which the DMA I/O library and the distributed file system client process are connected to each other through the VFS and the FUSE kernel module, and wherein the data channel is a path along which the DMA I/O library and the distributed file system client process are directly connected to each other.