Based on the analysis of data centre(DC) traffic pattern, we introduced a holistic software-defined optical DC solution. Architecture-on-Demand based hybrid optical switched(OPS/OCS) data centre network(DCN) fabric is introduced, which is able to realise different inter-and intra-cluster configurations and dynamically support diverse traffic in the DC. The optical DCN is controlled and managed by a software-defined networking(SDN) enabled control plane to achieve high programmability. Moreover, virtual data centre(VDC) composition is developed as an application of such softwaredefined optical DC to create VDC slices for different tenants. Based on the analysis of data center (DC) traffic pattern, we introduced a holistic software-defined optical DC solution. Which is is able to realize different inter-and intra-cluster configurations and dynamically support diverse traffic in the DC. The optical DCN is controlled and managed by a software-defined networking (SDN) enabled control plane to achieve high programmability. Moreover, virtual data center VDC) composition is developed as an application of such software defining optical DC to create VDC slices for different tenants.