Embodiments relate to a signal quality control method and a base station. The method includes: determining, by the base station based on a clipping threshold corresponding to each of the plurality of antennas, a time-domain noise signal for clipping a first time-domain signal of each antenna; performing time-frequency transformation on the time-domain noise signal of each antenna to obtain a first frequency-domain noise signal; processing the first frequency-domain noise signals of the plurality of antennas jointly to decompose the first frequency-domain noise signals into a second frequency-domain noise signal set in L flow directions and/or a third frequency-domain noise signal set in a complementary space of the L flows; and using the second frequency-domain noise signal set and/or the third frequency-domain noise signal set to clip the first time-domain signal set. According to the embodiments, noise signals are processed jointly.