Abstract: Solar energy is one of the leading energy in the future, and researches about solar cells are becoming hot spots gradually. Its properties under energetic particles irradiations have been widely characterized, but there is few about its laser-induced damage. So its necessary to study the laser-induced damage of solar cells. Behaviors of monocrystalline silicon solar cells under 532 nm 20 ns and 300 ps pulse laser irradiations were studied. Damage mechanism of monocrystalline silicon solar cells under the irradiations of ultrashort pulse laser was analyzed. When the single pulse energy was fixed, the relation among damage effect, pulse width and repetition frequency was described. The differences of damage mechanism between different types of laser were compared. Through the analysis, the principal factor of solar cells damage was pointed out, and the damage of solar cells induced by laser irradiation mainly relied on the thermal effect.