As one of key components of powder feeding system in the technology of laser rapid prototyping for metal powder, the powder feeding efficiency of powder feeding nozzles influences directly the laser rapid prototyping efficiency and accuracy of metal powder. The in-depth studies at home and abroad are performed in this field and a variety of new powder feeding nozzles are developed in which the coaxial powder feeding nozzle can effectively improve the metal powder cladding effect and utilization. The feeding principle and the research status at home and abroad of coaxial powder feeding nozzles are introduced, the main factors influencing powder utilization and laser-powder coupling performance are analyzed and summarized, and the improvement methods are proposed. Improvement approaches for laser focusing, powder segregation and bounce, and poor cooling efficiency are proposed, and the applications of coaxial powder feeding nozzles are prospected.