Abstract: Aiming at the current situation that the existing material system of micro-nano copper paste lacks systematic optimization, this paper deeply investigates the screening criteria and proportioning rules of key additives, targetting for improving the antioxidant property and bonding performance. Firstly, a combined modification process based on pickling surface treatment, high-speed centrifugation and vacuum drying was developed. The characterization results show that this process significantly inhibits the oxidation kinetics while maintaining the original micromorphology of copper powder. The oxygen content of the modified copper powder is only 0.371wt% after 10 days of exposure to air, exhibiting excellent chemical stability. Secondly, it is revealed that the influence weight of each component on the shear strength of the joint follows the order of dispersant > active agent > film-forming agent. It is clarified that the initial physical dispersion state of micro-nano particles is a prerequisite for determining the sintering performance, and the synergistic effect of compounded active agents in the medium and high temperature range effectively ensures a reductive atmosphere over the entire temperature range. Finally, the proportions of solvent, reducing agent and film-forming agent were systematically optimized based on orthogonal experiments. The optimal formula was determined, which consists of a solvent system with a specific ratio, a 4∶6 compound reducing agent and a modified rosin film-forming agent. The shear strength of the sintered joint prepared from this solder paste reaches up to 31.2 MPa, which meets the requirements of high-temperature semiconductor interconnection.