Abstract: Nano-technology as a new generation of quantum cellular automata(QCA) has developed at a high speed in recent years. With the purpose of improving the stability of QCA circuit, this thesis is going to provide a brand-new design. It suggests adopting tolerance fault one-bit full adder, then via the simulation and analysis by QCA Designer to check its feasibility and its tolerance of fault. This design, according to the author's view, would set a good example for the study of the complex QCA circuit.