Abstract: A finite element simulation about the forming principle and the process of clinched joint of aluminum alloy 5052 with segmented die was conducted, comparing with the simulation of integrate die and analyzing the metal flow in segmented die during clinching process. The samples of clinched joint with segmented die were prepared by anodizing the membrane and DIC was used for observing the microstructure of the clinched joint to analyze the metal flow in microscopic view. The results show that the simulation with segmented die obtained a better neck thickness and undercut, showing a good agreement with experimental results. Blocky grain of the microstructure in clinched joint changed into fibrous structure, with the grain stretched refining. And the flowing direction during the clinching process with segmented die of the simulation results was consistent with the experimental ones.