A method of preparing a copper-based composite conductive powder. The method includes: (1) preparing a liquid polyacrylonitrile (LPAN) solution, stirring the LPAN solution to yield a cyclized polyacrylonitrile solution; (2) heating the cyclized LPAN solution at between 200 and 300° C. for between 1 and 10 hrs to yield a thermally-oxidized polyacrylonitrile having a ladder structure; (3) adding the thermally-oxidized polyacrylonitrile and a copper compound to a solvent, and uniformly mixing, to yield a polyacrylonitrile coated copper compound; (4) drying the polyacrylonitrile coated copper compound to yield a carbonized precursor coated copper compound; and (5) calcining the carbonized precursor coated copper compound in the presence of an inert gas flow of between 10 and 500 mL/min for between 6 and 24 hrs at the temperature of between 300 and 1800° C.