The invention discloses a thermoplastic polyether ester elastomer composition as well as a preparation method and application thereof. The thermoplastic polyether ester elastomer composition comprises 80-100 parts of polyether ester elastomer and 0.1-2 parts of epoxy resin. The preparation method comprises the steps of adding the components to a high-speed mixer so as to be mixed at a high speed, and then adding the mixture to a double-screw extruder so as to be subjected to extruding granulation at 210-250 DEG C, thus obtaining the thermoplastic polyether ester elastomer composition. The thermoplastic polyether ester elastomer composition and the preparation method have the beneficial effects that by adding the epoxy resin to modify the polyether ester elastomer, the melt index of the material can be obviously reduced, the tensile strength of the material can be improved, the elongation at break of the material is relatively high, and the material has good resilience effect and good dynamic/static stiffness; the process is simple, and the production cost is relatively low; the thermoplastic polyether ester elastomer composition can be used in the fields such as track traffic gaskets and the like.