Abstract. In this paper, the effects of process parameters of Magnetic pulse welding (MPW) on the mechanical properties and microstructure of dissimilar metal joints of 6063-O and 20 steel tubes were investigated according to experiments. The experimental results show that the tensile strength of MPW joint is higher than that of the aluminium tube when the discharging energy of MPW attaches a certain value as well as the process parameters are reasonable, in which the mechanical joining was happened. Through the FEM analysis and experiments verification, the metallurgical joints were obtained with the moderate discharging energy, reasonable impact angle and radial gap. The results of micro hardness test show that the transition zone has a big change because the grain structure of joints in the interface was refined.