Abstract: To effectively prevent coal dust explosions caused by deposited dust in underground coal mines, a dust deposition intensity sensor was designed based on the sensing principle of a resistance strain cantilever beam. The sensor mainly consisted of a signal processing module, a dust deposition intensity detection unit, and a shielded connecting cable. The detection unit comprised a metal protective enclosure, an umbrella-shaped dust collection tray, a resistance strain cantilever beam, and an analog signal processing circuit. After dust settled on the collection tray, the Wheatstone full-bridge circuit in the resistance strain cantilever beam output a sensing signal, which was differentially amplified and converted from analog to digital by the analog signal processing circuit. The dust mass signal was thereby converted into a digital signal, and the dust deposition intensity was calculated based on the projected area of the umbrella-shaped collection tray. To avoid interference from on-site water flushing, the collection tray was designed with an umbrella-shaped structure. Testing and analysis determined its key parameters: a diameter of 70 mm and an inclination angle of 20°. Laboratory test results showed that the dust deposition intensity sensor exhibited good detection performance over a range of 0–100 g. The measurement error for deposited dust mass was less than 0.1 g, with a resolution of 0.01 g. The absolute error in deposition intensity measurement did not exceed 0.002 3 g/cm², with a resolution of 0.000 1 g/cm², and the repeated-test error did not exceed 0.000 7 g/cm². Field test results from a coal mine showed that the measurement error of the dust deposition intensity sensor did not exceed 0.002 5 g/cm².