The invention discloses a frequency-domain small wave blind equalization method based on united combining space-time diversity, comprising the following steps: firstly, realizing a single channel frequency-domain small wave blind equalization method (FWTCMA) by utilizing an FFT technique and an overlap retaining method; and secondly, constructing a united combining space-time diversity system model, wherein the united combining space-time diversity system model is characterized in that each branch path adopts different space diversity modules on the basis of time diversity; the output of combined space diversity modules is used as the input of a time diversity combiner; and a signal combined by the time diversity combiner is used as the input of a whole system. The frequency-domain small wave blind equalization method has high convergence speed, small steady state error and low computing complexity.