Aiming at high working power and heat dissipation of electronic components, this study developed a novel bionic fractal microchannel heat sink with traveling-wave fins based on fractal theory and disk-like tree-like structure. α-Al2O3-water nanofluid was chosen as the working fluid instead of water in the microchannel heat sink. Thermohydraulic performance of nanofluids in the bionic fractal microchannel heat sink with traveling-wave fins was simulated numerically, and its comprehensive performance was studied. The main control parameters of this study include the depths of the traveling wave structure (h=0.00005 m, 0.00010m, 0.00015 m, 0.00020 m, 0.00025 m), the eccentricity ratios of the traveling wave structure (e=0, 0.1, 0.2, 0.3, 0.4) and Reynolds numbers (Re=200-1,000). Results indicate that the surface temperature of the microchannel heat sink decreases with Reynolds number and depth of traveling wave structure. The use of traveling ribs at fractal corners can convert the inhomogeneous flow caused by the fractal effect into a stable horizontal channel flow more efficiently, while the temperature uniformity increases with depth and eccentricity ratio. Results also show that the traveling wave structure has the best overall performance when the eccentricity ratio of the traveling wave structure is 0.1 or 0.2, and the depth is 0.00020 m or 0.00025 m.