Abstract: In order to investigate solidification crack of SnAgCu solder joint on the print circuit board (PCB), solidification cracks during solidification are regenerated, the process of the solidification crack formation on the designed specimen is simulated, and the effect of the small element additions on the solidification crack formation of SnAgCu solder joint is researched.Experimental results indicate that some solidification micro-cracks exist significantly on the mini SnAgCu solder joint.The solidification crack susceptibility of Sn-Ag-Cu solder alloy is evaluated by the total crack length of the solder joint, adding trace amounts of Ni and Ce element can depress the solidification crack formation of the solder joints, but adding P element can aggravate the solidification crack formation of SAC305 solder joint and make the crack length evidently increase.