Abstract To prevent the harm of respirable dust and dust explosions, it is necessary to detect the concentration of dust generated in the process of bulk materials to help dust suppression. In this investigation, a dust concentration measurement method is proposed based on the eigenvalue calculation of image transmittance. The method is combined with the dark channel prior theory into the computer system and calibrated in the laboratory to calculate the transmittance of dust images. Furthermore, a dust concentration online measurement experimental platform is established to verify the correctness and reliability. Moreover, the industrial application is also carried out. The average relative error of dust concentration is 4.53%, and the relative error is less than 10% of the dust concentration measured by online measurement experimental platforms and industrial applications, which satisfied the measurement requirements. It is concluded that the measurement method has high applicability and can be practically applied to dust concentration measurements.