Abstract: The present invention provides a cloud data storage system and the method thereof. The system according to the present invention can acquire the statuses of the data source and the client device to generate a usage status data, and the usage status data are generated according to the requirements of the current connection and the files to be accessed. The data source can actively search the usage status data and enable the connection. Then, the system determines whether to access the digital content from the data source in order to transmit the digital content to the client device. The present invention provides a system and method which will not occupy the resources of the system, and will notify the client device that the physical storage device is in connection status and usable again after the physical storage device is temporarily disconnected or shut down.