In response to the issues such as the reduction in the acoustic wave intensity emitted by the ultrasonic transducer and the decrease in the sensitivity of the received signal of traditional ultrasonic anemometers under conditions like rain and snow, strong wind, dusty environments, and long-term usage, which subsequently lead to low measurement accuracy and low stability of wind speed and direction, an ultrasonic anemometers based on adaptive adjustment of signal gain has been designed. The electrical hardware section mainly consists of the driving circuit and receiving circuit for ultrasonic signal transmission, the programmable signal gain amplification and adjustment circuit, the filtering circuit, the AD acquisition circuit, and the MCU control circuit, etc. The software part mainly employs the time difference method, the ring tone method, the cross-correlation method, and the adaptive adjustment control algorithm of signal gain based on the binary search method to calculate the wind speed and direction. Experimental results indicate that the designed ultrasonic anemometer yields highly accurate and stable data for wind speed and direction measurements in harsh environments，Within the range of 0-15m/s, the error is ±0.5m/s; for wind speeds between 15-40m/s, the error does not exceed ±3%.The absolute error of wind direction is less than 3°.