In order to study the surface characteristics of exposed-aggregate cement concrete pavement, the measurement mechanism of surface texture depth was analyzed by using digital image technique. Based on the principle of least square and Table curve 3D software, two-dimensional digital image of road surface was reconstructed into three-dimensional space surface and a method of evaluating and measuring pavement surface texture depth was put forward. With this method， digital image samples were calculated and the results were compared with the results of conventional measurement method. The results indicate that exposed-aggregate cement concrete pavement has excellent road characteristics; there is a good correlation between the digital image technique and the traditional sand patch method and the relative error is less than 7 percent. Thus, the digital image technique is feasible in evaluating and measuring pavement surface texture depth.