现代工程结构要求对异种金属材料进行焊接。激光焊接具有密度高、焊缝深宽比大、热影响区窄以及变形小等特点，成为异种金属材料焊接的有效方法。异种金属激光焊接过程包含多种效应，机制复杂。比如，材料性能差异对焊缝微观组织与宏观性能的影响; 焊接熔池的形成、演化机制; 熔池凝固过程焊接缺陷及残余应力形成等。围绕异种金属激光焊接过程中的关键问题，国内外开展了诸多研究工作，对此进行了全面阐述。在此基础上，指出异种金属材料激光焊接研究中的不足及发展方向。

Advanced engineering structures require dissimilar metal jointing. Laser welding has such merits as high energy density, high depth-to-width ratio, narrow heat-affected zone and limited shape-deformation. Therefore, it becomes one of the effective approaches for jointing dissimilar metal combination. The procedure of laser welding for dissimilar metal is very complex.There are some key issues about laser welding mechanism, for instance, thermal-physical material properties, melt pool dynamics, melt-condensation mechanism, formation of welding defects and residual stress. The progress and present research of experimental and numerical simulation about these issues are discussed. On this basis, some problems of laser welding of dissimilar metal materials are put forward.