A high heat resistance composite separator comprising: a porous substrate having a plurality of pores; an inorganic coating layer formed on one surface of the porous substrate, the inorganic coating layer consisting of a plurality of inorganic particles and a binder polymer disposed on a portion or all of surfaces of the inorganic particles to connect and bind the inorganic particles; and a high heat resistance polymer coating layer formed on the other surface of the porous substrate, the high heat resistance polymer coating layer consisting of a high heat resistance polymer and inorganic particles dispersed in the high heat resistance polymer, wherein in the inorganic coating layer the amount of the binder polymer is in a range of 0.1 to 50 parts by weight based on 100 parts by weight of the inorganic particles; and in that in the high heat resistance polymer coating layer the amount of the inorganic particles is in a range of 0.1 to 40 parts by weight based on 100 parts by weight of the high heat resistance polymer, wherein the binder polymer is any one selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan and carboxyl methyl cellulose, or mixtures thereof, wherein the high heat resistance polymer is any one selected from the group consisting of aromatic polyamide, aromatic polyimide, aromatic polyamide-imide, aromatic polyimine, polytetrafluoroethylene, polybenzoxazole, polybenzimidazole, polyphenylsulfide and polyphenylene oxide, or mixtures thereof. a porous substrate having a plurality of pores; an inorganic coating layer formed on one surface of the porous substrate, the inorganic coating layer consisting of a plurality of inorganic particles and a binder polymer disposed on a portion or all of surfaces of the inorganic particles to connect and bind the inorganic particles; and a high heat resistance polymer coating layer formed on the other surface of the porous substrate, the high heat resistance polymer coating layer consisting of a high heat resistance polymer and inorganic particles dispersed in the high heat resistance polymer, wherein in the inorganic coating layer the amount of the binder polymer is in a range of 0.1 to 50 parts by weight based on 100 parts by weight of the inorganic particles; and in that in the high heat resistance polymer coating layer the amount of the inorganic particles is in a range of 0.1 to 40 parts by weight based on 100 parts by weight of the high heat resistance polymer, wherein the binder polymer is any one selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan and carboxyl methyl cellulose, or mixtures thereof, wherein the high heat resistance polymer is any one selected from the group consisting of aromatic polyamide, aromatic polyimide, aromatic polyamide-imide, aromatic polyimine, polytetrafluoroethylene, polybenzoxazole, polybenzimidazole, polyphenylsulfide and polyphenylene oxide, or mixtures thereof.