The overall performance of traditional network file system is affected by software overhead when using high-speed storage device. Therefore, a method of constructing a file system using SPDK (Storage Performance Development Kit) was proposed, and a prototype of a network file system RUFS (Remote Userspace File System) was realized on this basis. In this system, the directory tree structure of file system was simulated and the metadata of file system were managed by using key-value storage, and the file contents were stored by using SPDK. Besides, RDMA (Remote Direct Memory Access) technology was used to provide file system service to clients. Compared with NFS+ext4, on 4 KB random access, RUFS had the read and write bandwidth performance increased by 202.2% in read and 738.9% respectively, and had the average read and write latency decreased by 74.4% and 97.2% respectively; on 4 MB sequential access, RUFS had the read and write bandwidth performance increased by 153.1% and 44.0% respectively. RUFS had significant advantages over NFS+ext4 on most metadata operations, especially on the operation of folder creation, RUFS had the bandwidth performance increased by about 5 693.8%. File system service with lower latency and higher bandwidth can be provided by this system via making full use of the performance advantages of the high-speed network and high-speed storage device.