Based on the background that picosecond pulse width laser with multi-pulses damaging the solar cells, we use three methods that are the surface morphology, voltammetry characteristics and electrolumi-nescence of solar cells to obtain the damage characteristics of solar cells with the laser before and after laser ablation. A three-junction GaAs solar cell with pulse width of 15 ps and wavelength of 1 064 nm is irradiated by picosecond pulsed laser. By changing the laser irradiation power through repetition frequency regulation, the damage characteristics of grid line and non-grid line of solar cell under laser irradiation are analyzed. The experimental results show that, although the laser spot is small, the material inside the battery has been damaged. It's mainly because the damage of the ordered structure of the material inside the battery is gradually increased. When the laser power is higher, the internal damage area is larger. When the gate line is irradiated by laser, the fusion of the gate line will greatly affect the absorption of the carriers by the solar cell, thus reducing the photoelectric conversion ability of the solar cell, and then affecting the electrical performance of the solar cell, so that the damage effect of the gate line is stronger than that of the non-gate line.