Based on the causes and repair methods of particle gap, this paper analyzes the influence factors about the cell gap and head diameter for success rate. When the cell gap is different, the same pressure value has different success rate. The different cell gap has the differentiation of the optimal pressure value. When the cell gap is small, the pressure value required to achieve the best repair effect is larger, and vice versa. The change in the diameter of head directly affects the intensity of pressure acting on the TFT-LCD surface. With the intensity of pressure increasing, the success rate first increases and then decreases. The broken screen rate increases significantly after a certain pressure. The study shows that in order to ensure the repair effect of pressing particle gap in actual production, it is necessary to adjust the appropriate pressure for the different cell gap, and through the best intensity of pressure to select the appropriate diameter of head, to ensure a good repair effect.