Abstract: In this paper, a modified virtual crack closure technique proposed by author had been used to analyze the interface fracture of jointed area in multi-material components under a combined thermal and mechanical loading. Firstly, through the fracture analysis of a single leg bending (SLB) model which was established with a rubber sandwich under the different thermal loading, the rubber sandwich's influence on the energy release rate as well as each component was studied. Then, the interface fracture of typical multi-material cylindrical shell skirts composed by composite-rubber-metal under a combined thermal and mechanical loading, which had a heat flux boundary, was analyzed. It shows that the energy release rate of the interface crack gradually increases as the temperature rises. Lastly, the effect of the position of delamination and the thickness of the rubber on the energy release rate of each interface was discussed. It can be seen that there is a size effect between rubber thickness and interface toughness.