Abstract: HVDC transmission technology has the advantages of large transmission capacity, long transmission distance and low comprehensive cost, which plays a key role in solving the problem of reverse distribution of energy centers and load centers in China. It is an important strategic support technology for the implementation of "West-to-East Power Transmission" in China, accounting for more than 50% of the total capacity. After more than 20 years of application and development, China has built a power grid with multiple DC lines connected to the same area, forming a multi-infeed HVDC transmission system. Although this system improves the flexibility of the operation mode and expands the transmission capacity, the increasing complexity of its structure has made the system safe or stable problem more and more prominent. In the multi-infeed DC system, a single AC fault may cause multiple DC commutation failure in a wide range, causing tens of millions of kilowatts of power impact to the system and seriously threatening safety and stability of the power grid. The hazards caused by commutation failures are becoming more and more serious as the number and capacity of DC lines increase. Focusing on the problem of multi-infeed DC commutation failure in the future scenario of high proportion of new energy, this paper first explains the concept of multi-infeed HVDC transmission system, analyzes the commutation failure mechanism of DC transmission system, and then reviews the existing commutation failure prevention technologies from three levels, namely, station level, converter level, and system level. Finally, the prospects in the future commutation failure prevention technology is put forward, and relevant suggestions are given.