Abstract: The leaf vein structures in plants have undergone millions of years of evolution, exhibiting excellent heat transfer and fluid transport capabilities. Inspired by the curved leaf-vein structure, this study proposes a biomimetic leaf vein microchannel heat sink (LV-MCHS) for chip thermal management. Orthogonal experiments were performed to analyze the effects of microchannel height (h), lateral channel spacing ratio (γ), and lateral channel width ratio (β) on the initial design performance. A multi-objective optimization using Non-dominated Sorting Genetic Algorithm-II (NSGA-II) was conducted to obtain an optimized microchannel structure (NSGA-II -MCHS). To further evaluate performance, heat sinks were fabricated using Selective Laser Melting (SLM) technology, and experimental tests were conducted. Comprehensive analysis of numerical simulations and experimental results demonstrated that, at a Reynolds number (Re) of 524, the optimized NSGA-II MCHS reduced pump power (W_pp) by 12.3% and thermal resistance (R_th) by 3.07% compared to the unoptimized LV-MCHS. These results clearly highlight the significant advantages of the optimized MCHS in reducing both surface temperature and flow resistance.