Abstract: In order to evaluate the dynamic absorption of reconstituted tobacco base sheet to coating solution, contact angle technology was adopted to investigate the dynamic absorption effect of base sheet to coating solution and determine the key index of coating solution, and the causes of the color difference between the right and wrong sides of reconstituted tobacco were analyzed. The results showed that:1) The centrifugally purified coating solution was absorbed by base sheet rapidly, the permeation rate increased by 30%. 2) The viscosity of coating solution affected the absorption effect of base sheet obviously, it was a key index influencing coating quality. Decreasing the viscosity of coating solution properly could promote its permeation rate. 3) The right side of base sheet retained more long fibers, and more short fibers and fillers settled on the wrong side during base sheet making, the color of the wrong side was darker than that of the right side due to the faster absorbing speed of the wrong side to coating solution. 4) The color differential values of the right and wrong sides were 52.21 and 54.65 respectively, the difference value of 2.44 reached the upper limit of "perceivable" range, the color difference was obvious. Therefore, the dynamic absorption of the base sheet of paper-making process reconstituted tobacco to coating solution can be deeply analyzed by means of contact angle technology.