Method of characterizing and testing the optical performance of metal grid transparent conductive films (MG-TCF) has been established. Utilizing a charge coupled device (CCD) optical imaging device, light transmittance values of MG-TCF can be obtained by translating the CCD light response information into the light information. The average transmittance on different size scales, printed line width and the line edge roughness have also been established. Further more, combined with 3D graphical technique, the 3D transmittance display on pixel-level scale has been set up. The test results of three MG-TCF samples with square grids in flexographic printing show that the deviations of the light transmittance measured by an ultraviolet spectrophotometer are less than 1%. And thought the light transmittance analysis on pixel-level scale for the samples, characteristic values defined above have been calculated and used for demonstrating the sample features. Overall, the established method can characterize the MG-TCFs′ optical properties and give a more detailed analysis.