Based on the phenomenon of laser light intensity scintillation in the turbulent atmosphere, this paper builds a crosswind measurement system, proposes a maximum trend matching algorithm to match the trend sequence of the fitted laser echo signal, calculates the time delay of two echo signals, and deduces the synthetic wind speed on the entire path. The system and the standard wind measurement radar are used to simultaneously measure the target path of 117, 225, and 485 m respectively. The experimental results show that the correlation coefficients of the measurement data of two devices are 0.8567, 0.8327 and 0.7647, which are in good agreement. In addition, the system adopts a transceiver integrated configuration, compact structure, light weight, small volume, easy to carry, simple algorithm, and high measurement accuracy.