Polyamide-based composite resin composition having excellent gas barrier property

The present invention relates to a polyamide-based composite resin composition comprising: 30-80 wt% of a polyamide-based resin; 5-59 wt% of a meta-xylenediamine (MXD)-based modified nylon; 10-50 wt% of a thermoplastic olefin rubber comprising a maleic anhydride-grafted ethylene-octene copolymer, a maleic anhydride-grafted ethylene-propylene-diene monomer, or a mixture thereof; 0.5-10 wt% of clay; and 0.01-5 wt% of a carbon nanotube (CNT). According to the present invention, blow molding is easy, and mechanical properties such as low temperature impact and tensile strength are excellent and, simultaneously, a gas barrier property can be greatly improved.