A novel method for measuring the concentration of pure solutions based on the principle of light attenuation was developed. By measuring the transmitted light intensity of laser in sample solution and calculating the absorption coefficient according to Beer's law, the reliable measurement of low concentration solution was realized. At 532 nm wavelength, the concentration of a 0.000 1 mol·L^?1 copper sulfate solution measured by this method shows that the systematic error is controlled within 10%, and the absorption coefficient of copper sulfate solution measured is consistent with that reported in other literatures. The results show that this method has high accuracy and reliability, and can meet the requirements of low concentration solution measurement in related fields.