Abstract: The paper introduces the basic principle for mine air velocity measurement based on time difference, proposes a method using a pair of ultrasonic transducers to complete mine wind speed measurement; a mine-used ultrasonic wind speed sensor based on the method is designed. Based on DSP processor, related peripheral circuit interface is designed, and the method of adopting epoxy resin to cast part circuit for intrinsically safe processing is proposed. Experimental results show that the wind speed measurement range is 0.2 m/s to 40 m/s, and the measurement errors are controlled with±0.25 m/s in the wind speed range of 0 m/s to 25 m/s.