This paper aims to provide a method for improving the tribological properties of 316L stainless steels in seawater. During the experimental process, laser texturing technology was used to create biomimetic micro-textures inspired by turtle shell patterns on the 316L stainless steel surfaces. Then, CrAlSiN coating was deposited on the textured surface using the physical vapor deposition (PVD) technique, allowing us to study the frictional properties of the samples in both atmospheric and seawater environments. The results showed that, compared to polished 316L stainless steel, the specimens treated with micro-texture and CrAlSiN coating exhibited a reduction in wear rate by 52.1% and 71.8% under atmospheric and seawater friction conditions, respectively. Under atmospheric friction conditions, the micro-textures had a limited effect on reducing the friction of the 316L stainless steel substrate. However, the CrAlSiN coating, due to its excellent mechanical properties, significantly improved the wear resistance of the 316L stainless steel. Under seawater friction conditions, the continuous CrAlSiN coating played a role in reducing 316L stainless steel wear and seawater corrosion. At the same time, the micro-textures acted as reservoirs for wear debris and seawater, forming a more stable seawater lubricating film and reducing the friction coefficient. Therefore, the synergistic effect of the CrAlSiN coating and biomimetic micro-textures demonstrated remarkable improvement in the tribological performance of 316L stainless steel in seawater environments.