It's a great challenge to achieve the synchronous enhancement of the fracture toughness and strength via designing the microstructures of blend composites. Herein, multi-walled carbon nanotubes (MWCNTs) were incorporated into polyethylene terephthalate/ethylene butyl acrylate-glycidyl methacrylate terpolymer (PET/PTW) blend. Effects of MWCNTs on the mechanical properties, phase morphology, crystallization behaviors, heat resistance and antistatic property of the blend were investigated. It is found that MWCNTs are selectively located at the two-phase interface of the blend and induce epitaxial crystallization of PET matrix, which better strengthens the interfacial adhesion of blend composites. Tenacious interface endows blend composites with superior fracture toughness and strength. The impact strength and tensile strength of the blend composite only containing 0.5 wt% MWCNTs are as high as 72.3 kJ/m2 (without fracture) and 38.9 MPa, respectively. The toughening mechanisms are attributed to the role of MWCNTs in compatibilizing, stress transferring and hindering the rapid propagation of cracks at the interface of the blend. Moreover, MWCNTs endow the blend composites with outstanding heat resistance and antistatic property, which enlarges the application fields of PET. This work offers a dexterous and effective blueprint for manufacturing of high mechanical performances PET-based blend composites.