To enhance the performance of laser-induced breakdown spectroscopy (LIBS) for the analysis of element Cr in solutions, a surface-enhanced LIBS technique combining metallic microstructures is proposed. Initially, using femtosecond laser surface texturing technology, various shapes and cycles of microstructures including rectangles, circles, triangles, and hexagons were etched on the surface of metallic aluminum. Through comparative analysis, the effects of different microstructures on the surface-enhanced LIBS spectral intensity and stability of Cr-element aqueous solutions deposited on them were investigated. The results indicate that smaller microstructure cycles result in more significant spectral enhancement, with rectangular microstructures demonstrating the optimal spectral enhancement at the same period, increasing the spectral intensity by approximately four times compared to untreated metallic aluminum. Furthermore, hexagonal microstructures exhibit the best spectral stability and repeatability. These findings provide a viable method for substrate preparation for applying surface-enhanced LIBS techniques to the detection of heavy metal elements in aqueous solutions.