In order to analyze the damage evolution process of frame joints with concrete-filled square steel tubular column-unequal depth steel beam under earthquake,numerical analysis were carried out of joints by using the finite element analysis software ABAQUS based on the seismic performance tests of 4 frame joints with concrete-filled square steel tubular column-unequal depth steel beam,and a two-parameter seismic damage model suitable for such heterotypic joint was selected.Damage development process of frame joints with unequal depth steel beam under low cycle reversed loading was analyzed by finite element results and damage model.It is founded that the selected damage model can better reflect the damage evolution law of the joints from basically intact to completely destroyed than other damage model and quantitatively determine the damage limit of the joints with different damage levels.Seismic damage of the joints are mainly concentrated at bolt connection of upper and lower flanges of sorghum,and the damage accumulation increases with the increase of loading cycles,the ultimate failure mode is plastic hinge failure of sorghum.The conlusion provides theoretical basis for the damage-based seismic design method and seismic damage assessment of the joints.