Abstract: An aluminum plate exhibiting both super water absorption and super light absorption properties can effectively purify seawater or wastewater under solar irradiation. Femtosecond laser was used to scan the surface of aluminum plate, and prepare micro-groove structures with different sizes by adjusting the scanning speed. The water absorption and light absorption properties were measured, and the mechanisms of super water absorption and super light absorption were explored. The results indicate that the prepared groove structures endow the surface with anti-gravity super water absorption capability and strong super light absorption capability. At the scanning speed of 6.272 mm/s, the width, depth and uniformity of the grooves are optimized, resulting in the highest water absorption rate of 13.6 mm/s on the aluminum plate surface, the light absorbance all exceeds 91% and the best absorbance of 94.7% for ultraviolet light. The super water absorption is attributed to the enhanced surface capillarity due to the attachment of a large number of nanoparticles on the groove surface. The super light absorption is due to the continuous reflection and subsequent absorption of incident light by the ridge-valley structure of the grooves, which improves the broadband absorption performance of the surface for sunlight. The results of energy dispersive spectroscopy(EDS) show that at the edge of the groove on the aluminum plate, the contents of oxygen and carbon elements are higher than those at the middle position of the ridge, while the content of aluminum element is relatively lower. This is because the edge of the groove is closer to the laser ablation area, thus making its oxidation reaction more intense.