Abstract: In order to achieve tritium self-sustaining and energy amplification of the magnetic confinement fusion reactors, sub-critical blanket and tritium breeding blanket were set around the plasma region. We adopted natural uranium alloy as fuel, light water as coolant and moderator and embedded pressure tube sub-critical blanket as blanket design. By the analysis of neutronic physical properties, structural concept design, thermal-hydraulic performance and reactor safety, it shows that the multiplication factor may reach 10, tritium breeding ratio is greater than 1.15, and the blanket keeps in a deep sub-critical state and shows good heat safety performance. Based on the recently available fusion technology, we are striving to achieve the early commercial use of fusion energy and provide a competitive technology options for the sustainable development of China's energy.