Disclosed are a device and method for implementing combination and splitting of carrier frequency signals. The method comprises: at least two first band-pass filters respectively implement band-pass filtering on at least two carrier frequency sending signals; an annular combiner/splitter combines the at least two carrier frequency sending signals after band-pass filtering by the first band-pass filters, and sends the combined signals to a signal converter; the annular combiner/splitter sends the signals converted by the signal converter to at least two second band-pass filters; and the second band-pass filters implement band-pass filtering on the signals converted by the signal converter to obtain at least two carrier frequency receiving signals, wherein the annular combiner/splitter is formed by cascading of at least three circulators, the frequency bands of the first band-pass filters comprise frequency bands of service signals in the corresponding carrier frequency sending signals, and the frequency bands of the second band-pass filters comprise frequency bands of service signals in the corresponding carrier frequency receiving signals.