A new design method of triple-modular self-repairing redundant fault-tolerant circuits with different structures is proposed.A new function is designed to measure the difference of structures.Using the selfdesign and self-repair of evolvable hardware

triple-modular redundancy is implemented that has the same capability with the N-modular redundancy.Firstly

genetic algorithm is used to generate circuits.When the generated circuits’ totality is three or more

the difference function will be used to evaluate them and three best circuits are reserved.They will be applied in the system when the stop condition is satisfied.If any fault is occurred accidentally

the fault circuit will be separated from system.After it is repaired and inserted again

the system will have the same fault-tolerant capability with the original.So it improves the fault-tolerant capability

and has advantages of small volume

low cost

low power and didn’t affect the system’s function.The effect is validated by the 2 bits comparator with FPGA.The effect of the difference function is analyzed in the design process.The experimental results prove that the new method is feasible and the designed system is reliable rarely.