As an important energy source of solid rocket motors, the mechanical properties of composite solid propellants have always been the focus of attention in the engineering field. The macroscopic constitutive model and the fine-scale mechanical model in the characterisation of propellant mechanical properties was focused on. The development of the two types of models was systematically sorted out. The differences between the models were clarified. The applicable conditions of various models were pointed out. The difficulties and challenges of macro and fine mechanical models in the characterisation of propellant mechanical properties at the present stage were analysed. The proposal of mechanical models represented by cross-scale mechanical models will help to solve the problem of propellant mechanical property characterisation. The key in the future modelling of propellant mechanical characterization is the experimental research under complex conditions, focusing on the development of high precision and high performance multiscale numerical computation methods, as well as the integration of data-driven technology represented by artificial intelligence technology into model innovation.