Based on the ablation mechanism of femtosecond laser, the theoretical model of ITO area blackening method for repairing bright spots was established and verified through experiments, and in order to improve the success ratio of repair, the influence of various process parameters were also analyzed on the remediation effect. In this work, the repair mode was firstly established by a series of experiments with light detection test, microscope images and Focused Ion Beam(FIB) images. Then, process parameters that effect success ratio were analyzed by contrast experiments, and these parameters included the energy density per unit area of single-pulse laser, scanning speed, the laser frequency and sport size. Finally, in order to deeply analyze the ablation mechanism of ITO area blackening method, the variable “w” containing all process parameters was proposed and verified, and it successfully provides a theoretical basis for improving the success rate. Experimental results indicated that, when the spot size was 4.0~10.0 μm, energy density per unit area of single-pulse laser was 1.0 mJ/mm2 or more, and the “w” was 4 250 ~ 12 500 mJ/mm2, the blackening effect of ITO after repairing was up to the dark point standard and other undesirable phenomenon was not produced. According to the experimental result, the theoretical model and process parameter analysis was applied to mass production, the success rate of bright spot defective repair reached to 95.5%.