A recoverable and fault-tolerant CPU core and a control method thereof are provided. The recoverable and fault-tolerant CPU core includes first, second, and third arithmetic logic circuits configured to perform a calculation requested by the same instruction, a first selector configured to compare calculation values output from the first, second, and third arithmetic logic circuits by the same instruction, determine as a normal state when two or more of the calculation values are the same, and if not, determine as a fault state, and a register file configured to record the calculation value having the same value, when determining as the normal state in the first selector.