This invention discloses a multi-user data storage service system including a communication module undertaking communication tasks of TCP/IP network to guarantee the compute and order transmission of data on the communication layer, a user module discriminating the access requirement of the customer end, an ISCSI protocol module transforming ISCSI and standard SCSI instructions, a multi-user document system module setting up an independent disk for every user based on the user access ways and converting the block data operation request of each user to the access to file data directly and a management module managing the above mentioned modules to coordinate their operation.