Meso topography is used to examine the damage degree of lead-free Sn-Zn solder. Real-time meso topography is observed using scanning electronic microscope(SEM), which is assembled in a loading machine. The solder’s deformation and fracture is simulated using a damage accumulation process. The observed meso-structure evolutionary processes of the solder material is then analyzed according to the macro-meso combined mechanism. Some image processing technique are used. A new model of fracture mechanism and degree of damage is proposed.. that We show that the proposed meso structure evolution equations can accurately model the degree of material damage.