With the continuous reduction of integrated circuit chip size, the size of interconnects is gradually approaching the nanoscale, and interconnects have gone through materials from aluminum to copper, and now the metal cobalt that may replace copper. At present, mainstream chips still use copper as interconnection material, and the electromigration behavior under the condition of mechanical, thermal and electrical multi field coupling is an important factor affecting the reliability of small size copper interconnection. The development history of interconnect materials is introduced, and the advantages and disadvantages of aluminum and copper as interconnects are emphatically compared. It is pointed out that metal cobalt has advantages in resistivity and electromigration resistance, and is expected to become a new generation of interconnect materials. Then, the problems faced by small size copper interconnects are introduced, such as the increase of resistivity and electromigration. The influence factors of copper interconnection electromigration in microcosmic, macroscopic and technological aspects are emphatically discussed, and the finite element method, phase field method, entropy damage model, etc. for predicting electromigration are introduced. Finally, the technical problems faced by copper interconnects are further summarized, and the development strategies and research directions that are expected to improve electromigration are pointed out, providing important reference for the design of highperformance copper interconnection materials.