A new method is proposed for measurement of aerosol extinction coefficient by taking advantage of the characteristic of light transmission through coated glass tubes. When a ray of light of a particular wavelength penetrates through a glass tube filled with aerosols at a certain angle, the optical path length will be greatly increased due to multiple reflection of the light on the tube wall, and the amount of light diminished by aerosols can be measured by the sensors at both ends of the glass tube. The ratio calculation method is used to remove the effect of measurement errors caused by the light intensity fluctuation, uneven tube wall, molecular scattering, etc. during the photoelectric conversion. The sensitivity for measuring the extinction coefficients of aerosols is raised. Finally, this method is used to measure the extinction coefficients of aerosols in the wavelength of 550 nm. Compared with the results obtained with a visibility meter, the results obtained with this method are reasonable. In addition, based on simple principles, this method can be easily applied.