By measuring time lagged cross correlation function with a pair of sub-apertures of Shack-Hartmann wave-front sensor, the path-averaged transverse wind speed and wind direction can be found directly from the slope of this function with no time delay. Experiential formula to calculate the path-averaged wind speed is deduced. And the experiment on it in 1000 m horizontal propagating path was carried out for the first time by use of a Shack–Hartmann wave-front sensor. Some results were found. Firstly, the correlation coefficients of wind speed reach 0.988 from different pairs of sub-apertures; secondly, the results from different pairs of sub-apertures were averaged, and the variation trend was in accord with gained from an anemometer placed in the 15-m tower. The correlation coefficients of two typical experiments are 0.848 and 0.820 respectively. All the experimental results indicate that measuring path-averaged transverse wind speed by Shack-Hartmann wave-front sensor is feasible, which extends the function of this sensor.