As one of the mechanically vulnerable components in the structure of solid rocket motors， it is extremely important to clarify the physical and chemical properties of the interface for solid propellants， damage evolution patterns， and the effect of dewetting on the integrity of the propellant grain structure. Compared with experiments， numerical simulation can quickly and efficiently study the different physicochemical properties of various interface systems， and has good application prospects. From the microscale molecular dynamics that can reveal the mechanism of experimental phenomena from a molecular perspective， the mesoscale finite element numerical simulation considering the microstructure of complex filler particles and other materials in solid propellants， and the macroscopic numerical simulation closely related to the macroscopic mechanical response， the research progress of various interface mechanical properties for composite solid propellants was reviewed， the driving effect of numerical simulation for composite solid propellant interfaces at multiple scales on solid propellant engineering design at multiple scales and the current shortcomings were discussed， and the future development directions were also put forward.