The invention discloses a secondary correlation time delay estimation method for monitoring wind speed of supersonic wave of a wind power station and uses a data collection device to collect emission signals of paired supersonic probes. The secondary correlation time delay estimation method comprises steps of constructing a function of supersonic echo signals received under ideal conditions of tailwind and headwind, calculating a cross-correlation function of a formulation of the supersonic echo wave signal received under states of tailwind and headwind and determining the function as a first cross-correlation function, constructing a function of supersonic echo wave signals received by each supersonic probe of the paired supersonic probe under a condition of no noise and no wind; calculating correlation a function of two supersonic echo wave signal formulations and determining the correlation function as a second cross-correlation function; constructing a correlation function of the first cross-correlation function and the second cross-correlation function, calculating the correlation function of the first cross-correlation and the second cross-correlation function, performing peak value detection on the correlation function to obtain time difference so as to calculate the time delay estimation value and achieve accurate estimation of time delay.