A personal computer system for a mobile terminal user and an operation method thereof are provided. The personal computer system includes multiple main boards on which at least one software is run, multiple storage devices that are each configured to store at least one software to be used by a mobile terminal user allocated to the storage device, and a relay board system configured to select one main board in standby mode from among the multiple main boards and connect the selected main board to one storage device that is allocated to a mobile terminal user among the multiple storage devices in response to an access request from the mobile terminal user to run software, and to disconnect the selected main board from the allocated storage device in response to a request for termination of use of the selected main board from the mobile terminal user.