Several nano-nucleating agents were blended with linear PA6 (L-PA6) and long-chain branched PA6 (LCB-PA6) to prepare nanocomposites. The rheological behavior characterization founds that the nano-nucleating agent has little effect on the rheological behavior of L-PA6, but significantly improves the melt strength of LCB-PA6. The non-isothermal crystallization kinetic characterization founds that nanographite and MWCNTs can effectively improve the crystallization rate and crystallization temperature of PA6. Through the characterization of the cell morphology, it is found that the addition of nanographite has the greatest improvement in the foaming performance of L-PA6. The cell density of which at 250 ℃ is 1.66×10⁷ cm^-3, which achieves more than 3 times of pure resin. The effect of adding MWCNTs on the heterophasic nucleation of LCB-PA6 is the best, which can effectively reduce the dependence of LCB-PA6 on foaming temperature. Through mechanical property test, it is found that the low interface binding force between carbon tube and LCB-PA6 results in lower tensile modulus and flexural modulus for the LCB-PA6 nucleated modified foamed material. Due to the polarity of the hydroxyl groups on the surface of MWCNTs-OH, the interface binding force with LCB-PA6 is increased, and the tensile modulus and flexural modulus of LCB-PA6 are significantly improved. Due to the high-strength layered structure of nano-graphite, the tensile modulus and flexural modulus of L-PA6 are greatly improved.