The mechanical performances of cryogenic composite tanks need strict evaluation due to its extreme temperature condition of service. In this paper, a trans-scale modeling strategy is developed for the failure analysis of cryogenic composite structures, which is based on theories from micromechanics to continuum mechanics. Micromechanical model of representative volume element is developed to obtain the thermo-mechanical coupling properties of materials in the composite structure. Continuum mechanics model is sub-sequentially developed to predict the fields of physical properties in the composite structures. The predictions of performances of composite structures at cryogenic and different temperatures are of good agreement with conventional theoretical solutions. Numerical examples of cryogenic composite tanks indicate that the large temperature change can directly cause the fracture of matrix that can result in the overall failure of composite tanks. In addition, the thermal–mechanical coupling effect can reduce the prediction of critical thermal loads in the failure analysis of cryogenic composite tanks, which is more favorable for engineering designs due to the strict requirements of safety.