The invention discloses a virtual file system based on cloud computing. The virtual file system based on cloud computing comprises a serving terminal and a client terminal, wherein the serving terminal is composed of a file virtualizer, a file processing center, a file system interface, a file transmitter, a user interface, a database, a thumbnail managing module, a file format converting module and a rubbish cleaning device and the client terminal is composed of a receiving and transmitting module, a terminal simulation virtual file system and a file interaction module. The serving terminal interacts with one or more client terminals, so that the functions of carrying out asynchronous operation and asynchronous reading and writing on cloud terminal server files are provided for the system and applications based on the web. An effective solution is provided for the application of HTML5 to support a file system and an API is opened for the application of the third party. The auxiliary technology supporting file format conversion provides a substitute scheme when files which are not compatible with the HTML5 are browsed or edited. A file storage scheme of a cloud terminal is adopted so that a user can manage, browse and edit files without domain limitation, terminal limitation and platform limitation under network connection.