Comparing with traditional welding technology, there are many advantages of magnesium laser welding, for example, high welding speed, low line energy, small welding distortion, easy to achieve automate production et al. It is widely used in the area of magnesium welding. Fine microstructure and excellent weld shape can be obtained by choosing reasonable technology parameters and the mechanical properties of welding joint can also be promoted. But there are some defects in the process of welding magnesium alloys with laser, such as, stomas, cracks, impurities and so on. Some actions can be taken to improve or prevent those defects. For example, choosing the appropriate process parameters can solve the problem of cracks, impurities. In this paper, the status of laser welding magnesium alloy is reviewed in recent years, and some problems in magnesium laser welding were analyzed and some suggestions of solving the problems were put forward.