Abstract: An optical virtual-circuit-switching network system and optical switches thereof are provided. The optical virtual-circuit-switching network system includes multiple optical switches. Each optical switch includes an optical outbound handling module, an optical pass around module, and an optical inbound handling module. The optical outbound handling module transmits optical signals to both the horizontal optical network subsystem and the vertical optical network subsystem. The optical pass around module transmits optical signals from the horizontal optical network subsystem to the vertical optical network subsystem, or transmits optical signals from the vertical optical network subsystem to the horizontal optical network subsystem. The optical inbound handling module outputs the selected optical signals to dense wavelength-division multiplexing transceivers and, through these transceivers, converts the optical signals into electrical signals before forwarding the data to the top-of-rack switches.