Gold-tin solder had the advantages of high strength， good oxidation resistance， fatigue resistance， excellent screw performance and so on. It was more and more used in hybrid integrated circuits， especially in high power and high reliability integrated circuits to reduce package thermal resistance and improve the reliability of chip welding through eutectic welding. The foundational characteristics of the domestic gold-tin solder was analyzed，the key parameters of friction eutectic welding for power chip were studied by manual method based on domestic gold-tin solder.The reliability of gold-tin solder of power chip in space application was verified. The results show the shear strength meets the requirements of administrator and remains stable after a series of rigorous thermodynamics tests in aerospace environment， which shows the high reliability of welding.