A method for all-optical frequency multiplication/recovery based on the semicon-ductor optical amplifier(SOA)ring cavity with the interference is proposed and demonstrated by numerical simulation. This technique can be used to generate low clock amplitude jitter and input polarization independent pulse trains with the repetition rates of 5～25 GHz from 2.5 GHz driving pulse. Bias current of SOA effect on the amplitude of the output pulse train is great,and there is an optimized bias current of SOA for the base frequency of the 2.5 GHz and 10 GHz,respectively. In addition,this scheme can be applied to the extraction of the clock signal from a pseudorandom bit sequence signal.