Abstract: Aiming at the deburring challenge of deep cross-hole structures in liquid-cooled heat exchange systems of aerospace electronics, this study proposes a ternary synergistic process combining customized tool design, parameter optimization, and auxiliary polishing. Through the development of elastic-edge specialized tools and the establishment of a parameter system matching hole diameters （Φ0.8-Φ8.0）, the burr removal rate at cross-hole intersections reached over 99%. Experimental results showed that the first-time pass rate was improved from 75% to 99%, with a 18.7% reduction in flow resistance and 12.3% increase in heat dissipation efficiency. The successful application in a liquid-cooled chassis heat sink component verified the economic and technical feasibility of the proposed method, providing a transferable solution for complex flow channel processing in aerospace electronics.