Microchannel heat exchangers, including a bionic secondary branch (MHE-BS), complete vein bionic branch (MHE-CVB), and incomplete vein bionic branch (MHE-IVB), were designed based on the straight secondary branch (MHE-SS) inspired by the leaf vein structure of Parashorea chinensis. ANSYS FLUENT software was utilized to simulate the flow and temperature characteristics of 20 ℃ cooling water entering these heat exchanger structures under a constant heat flux of 50 kW/m² at different inlet Reynolds numbers (Re=660.07, 990.10 and 1320.13). The research findings indicate that multistage bionic channel structure can significantly enhance the overall heat transfer performance of the heat exchanger, with MHE-CVB showing more than a 35% reduction in inlet and outlet pressure drop compared to MHE-SS under different working conditions. In addition, it showed an decrease in surface temperature by over 2 ℃ and a strengthening factor for comprehensive heat transfer performance exceeding 1.2.