Abstract: According to aerodynamics,plasma spray theory and the idea of "expert in one thing and good at many",multi-functional microplasma spraying systems were developed.The IGBT inversion technology,micro-computer control engineering,soft switch technology,Laval nozzle structure and center axial powder feed were adopted in the designs of micro-plasma spraying systems,which made it possess the characteristics of small volume,light weight,strong anti-jamming,accurate control,high velocity of spray particles,high deposit efficiency of powder and high reliability etc.The system can produce different kinds of high quality coatings.The experimental results show that the bonding strength and microhardness of nano-structured Al₂O₃+13%TiO₂ coatings produced by multi-functional micro-plasma spraying are better than those of the same coatings produced by 9M plasma spraying.As the result,the coatings whose properties are equavitent of those of the coatings produced by conventional plasma spraying can also be deposited by multi-functional micro-plasma spraying with lower power by means of improving power design,spray gun structure and powder feed method.