Polyamide 6/Macrogol/attapulgite (PA6/PEG/AT) nanocomposites were synthesized by the two-step-melt polymerization method, in which firstly PA6/AT oligomer was prepared through in-site polymerization and then the corresponding nanocomposite was synthesized by the block copolymerization between PA6/ AT hard segment and Macrogol (PEG) soft segment. Additionally, PA6/PEG/AT nanofibers were made. The results demonstrated that the AT added into the PA6/ PEG system promoted the heterogeneous nucleation, and thus increased the crystallizability. And with the increase in AT content, the crystallization temperature, the temperature of thermal decomposition and mechanical intensity of nanocomposites all increased; and meanwhile both the elasticity, and the melting drip and smog from burning PA6/PEG/AT fibers obviously decreased. Then nanocomposites with lower AT content possessed higher elasticity and better dispersion of the filler. Thus, heat-resistant and flame retardant composites with high intensity or high elasticity can be prepared by means of adjusting the right proportion of