A method for producing a polyamide resin composition containing a crystalline polyamide resin containing a polycaproamide resin as a main component, a semi-aromatic amorphous polyamide resin, an inorganic reinforcing material, a master batch of carbon black, and a copper compound, wherein: the polyamide resin composition contains glass fiber (C-1), needle-shaped wollastonite (C-2), and a plate-shaped crystal inorganic reinforcing material (C-3) as the inorganic reinforcing material; a melt mass flow rate of the polyamide resin composition at a moisture content of 0.05% or less is 4.0 g/10 min or more and less than 13.0 g/10 min, the MFR being measured according to the description; a temperature-lowering crystallization temperature of the polyamide resin composition, the temperature-lowering crystallization temperature being measured with a differential scanning calorimeter according to the description is 180°C or higher and 185°C or lower; a mass ratio of to satisfies 0.5 < / ≤ 0.8; when the total of,,, and is 100 parts by mass, the content of is 0.001 to 0.1 parts by mass; the content of each of the components satisfies the following formulae: 30 parts by mass ≤ + + ≤ 60 parts by mass; 13 parts by mass ≤ B ≤ 23 parts by mass; 1 part by mass ≤ D ≤ 5 parts by mass; 20 parts by mass ≤ C − 1 ≤ 40 parts by mass; 8 parts by mass ≤ C − 2 ≤ 25 parts by mass; 8 parts by mass ≤ C − 3 ≤ 25 parts by mass; and and 40 parts by mass ≤ (C-1) + (C-2) + (C-3) ≤ 70 parts by mass; a dispersion liquid of the copper compound has a concentration of 0.04% by mass to 1.0% by mass; and the crystalline polyamide resin containing a polycaproamide resin as a main component, the semi-aromatic amorphous polyamide resin, the master batch of carbon black, and the dispersion liquid of the copper compound are mixed in advance, followed by charging the mixture is into a hopper part of an extruder, and charging the inorganic reinforcing material into the extruder by a side feed method. the polyamide resin composition contains glass fiber (C-1), needle-shaped wollastonite (C-2), and a plate-shaped crystal inorganic reinforcing material (C-3) as the inorganic reinforcing material; a melt mass flow rate of the polyamide resin composition at a moisture content of 0.05% or less is 4.0 g/10 min or more and less than 13.0 g/10 min, the MFR being measured according to the description; a temperature-lowering crystallization temperature of the polyamide resin composition, the temperature-lowering crystallization temperature being measured with a differential scanning calorimeter according to the description is 180°C or higher and 185°C or lower; a mass ratio of to satisfies 0.5 < / ≤ 0.8; when the total of,,, and is 100 parts by mass, the content of is 0.001 to 0.1 parts by mass; the content of each of the components satisfies the following formulae: 30 parts by mass ≤ + + ≤ 60 parts by mass; 13 parts by mass ≤ B ≤ 23 parts by mass; 1 part by mass ≤ D ≤ 5 parts by mass; 20 parts by mass ≤ C − 1 ≤ 40 parts by mass; 8 parts by mass ≤ C − 2 ≤ 25 parts by mass; 8 parts by mass ≤ C − 3 ≤ 25 parts by mass; and and 40 parts by mass ≤ (C-1) + (C-2) + (C-3) ≤ 70 parts by mass; a dispersion liquid of the copper compound has a concentration of 0.04% by mass to 1.0% by mass; and the crystalline polyamide resin containing a polycaproamide resin as a main component, the semi-aromatic amorphous polyamide resin, the master batch of carbon black, and the dispersion liquid of the copper compound are mixed in advance, followed by charging the mixture is into a hopper part of an extruder, and charging the inorganic reinforcing material into the extruder by a side feed method.