Suffering brittleness in ambient temperature, the application of bulk metallic glasses (BMGs) is limited. To overcome that, bulk metallic glass composites (BMGCs) were manufactured by in-situ introducing bcc B2 phases into the glassy matrix, which have been demonstrated appreciable ductility combined with strong work-hardening behaviors at room temperature. Furthermore, several previous studies have verified that high strength and plasticity can be simultaneously achieved for BMGCs at cryogenic temperatures. However, the intrinsic deformation mechanism of BMGCs at cryogenic temperatures has not been revealed in details. In this proposed work, it is expected that the results obtained from these in-situ low temperature neutron diffraction experiments will offer more insights into the effects of cryogenic temperatures on the structural evolution and mechanical performance of BMGCs.