Abstract: The present disclosure provides a method and device for unifying frame rates. The method includes: increasing rate on at least one of OTU frames that have different frame rates, so that the OTU frames can be processed at a receiving end by using a clock signal of a same frequency point; and after the rate increasing is performed, sending, on a wavelength division line, the OTU frames that have different frame rates. According to embodiments of the present disclosure, a same local crystal oscillator may be used at the receiving end to provide a clock signal for received wavelength division service frames.