A file access method, wherein the method is applied to a storage device in which a file system is established in a memory, the memory is a non-volatile memory NVM, and the method comprises: receiving a first access request, wherein the first access request carries a first file identifier and a start address of the first access request, and the first file identifier is used to indicate a to-be-accessed first target file; obtaining an index node of the first target file according to the first file identifier, wherein the index node of the first target file comprises information about first virtual space used to manage the first target file, the first virtual space is contiguous address space virtualized according to first physical space in the memory, the first physical space is used to store the first target file, the first virtual space is a part of preset global virtual space, the global virtual space is contiguous address space virtualized according to second physical space in the memory, and the second physical space is used to store all data in the file system; establishing a first mapping relationship between the first virtual space and second virtual space of a process, wherein the second virtual space is a segment of contiguous virtual address space in user space of the process; determining, from multiple disposed registers, a to-be-accessed register as a file management register according to a start address of the second virtual space, wherein the file management register stores a base address of a page directory of a global file page table, and the global file page table is used to point to a physical address of the first target file in the memory; converting the start address of the first access request into an access address of the first virtual space according to the first mapping relationship, wherein the start address of the first access request is an address in the second virtual space of the process; and accessing the file management register according to the access address of the first virtual space, to obtain the physical address of the first target file in the memory. receiving a first access request, wherein the first access request carries a first file identifier and a start address of the first access request, and the first file identifier is used to indicate a to-be-accessed first target file; obtaining an index node of the first target file according to the first file identifier, wherein the index node of the first target file comprises information about first virtual space used to manage the first target file, the first virtual space is contiguous address space virtualized according to first physical space in the memory, the first physical space is used to store the first target file, the first virtual space is a part of preset global virtual space, the global virtual space is contiguous address space virtualized according to second physical space in the memory, and the second physical space is used to store all data in the file system; establishing a first mapping relationship between the first virtual space and second virtual space of a process, wherein the second virtual space is a segment of contiguous virtual address space in user space of the process; determining, from multiple disposed registers, a to-be-accessed register as a file management register according to a start address of the second virtual space, wherein the file management register stores a base address of a page directory of a global file page table, and the global file page table is used to point to a physical address of the first target file in the memory; converting the start address of the first access request into an access address of the first virtual space according to the first mapping relationship, wherein the start address of the first access request is an address in the second virtual space of the process; and accessing the file management register according to the access address of the first virtual space, to obtain the physical address of the first target file in the memory.