Atomic simulations using classical mechanics formalism are used to investigate the interfacial binding between CNTs and silicon nanowires as well as mechanical properties of the CNTs encapsulated silicon nanowires systems. The simulations provide the effect of temperature, systems' cross-sectional radius, interfacial distance, applied tension on their binding degree and deformation behaviors. The simulation results reveal that the spacing and interfaces between CNT and nanowire significantly affect thermal stability and the degree of interfacial binding in the systems. The Lode-Nadai values' distributions in the systems provide insight into the loading states on the atoms both in CNTs and silicon nanowires during tension. The atomic hydrostatic pressures can be used to identify stress-transfer paths in the systems during the elasticity, plasticity, and fracture stages.