Due to the high variability of the thread placement, the achievable high degree of automation and the good mechanical properties textile reinforcements are used in highly loaded fiber reinforced polymer structures. A specific role is played here by 3D textile reinforcements with stretched thread arrangements, for example in the form of 3D fabrics and multi-layered weft knits. In addition to excellent stiffness and strength, they provide a high resistance to delamination as well as good drapability due to the mesh thread arranged in the thickness direction securing the thread system. In this work a novel degradation model for cyclically loaded textile-reinforced polymers on the basis of continuum damage mechanics approaches is developed. For this purpose, the damage phenomenology is investigated and classified for glass fiber multi-layer weft knit reinforced epoxy resin in uniaxial as well as in-phase multiaxial cyclic loading. In extensive tests load-specific damage can be observed - in the fracture modes already identified for quasistatic stress - which characteristically develop over the course of the cyclic load and show a clear dependence on the type and direction of loading. In the multi-axial load tests, the hitherto unknown coupling of the tensile and shear stiffness or compression and shear stiffness could be quantified and correlated with the occurring damage phenomena. The characteristic values and model parameters necessary for calibrating the material model are determined by means of single- and multi-axial constant amplitude tests by evaluating the stress-strain hysteresis and the S-N curves. The potential of the presented layer-wise fatigue damage model is demonstrated in selected validation experiments. In addition to the realistic modelling of the degradation behaviour, a very good prediction of the direction-dependent residual strength after cyclic loading is achieved. For the first time, the degradation model developed here provides the essential layer-related information on the state of the material during cyclic loading and is an essential building block for the comprehensive lifetime analysis of textile-reinforced composite structures.