Embodiments of this application provide a flash interface controller and an operation command processing method, and relate to the field of data storage. Programmable first type microcode and second type microcode are introduced to a flash interface controller. The first type microcode can be modified through programming to adapt to a procedure of parsing an operation command of a new protocol, and the second type microcode can be modified through programming to adapt to a flash bus operation required by a new flash interface standard. An operation command can be parsed by only fixing logics of physical modules in the flash interface controller and reading first type microcode and second type microcode that are related to the operation command. Therefore, various protocols and flash interface standards can be adapted to, and flexibility is good.