The invention discloses a polyamide (PA)/aluminum/polyvinylidenechloride (PVDC) composite food packaging film and a preparation method thereof. The preparation method comprises the following steps: (1) mixing PVDC, acrylonitrile-butadiene-styrene (ABS), sodium bicarbonate, diatomite, xylitol, iso-octyl methacrylate, magnesium stearate and titanium pigment to obtain a first mixed product; (2) mixing PA, polyvinylpyrrolidone, nano kaolin, sodium humate, sodium carboxymethylcellulose and silicon micropowder to obtain a second mixed product; and (3) pretreating an aluminum foil, coating a binder on the two sides of the aluminum foil, and hot pressing and forming the first mixed product and the second mixed product on the two sides of the aluminum foil in sequence to obtain the thermal insulation PA/aluminum/PVDC composite food packaging film; wherein the binder is prepared from starch, beta-cyclodextrin, polyvinyl alcohol, sodium borate, magnesium sulfate, cellulose acetate and water. The PA/aluminum/PVDC composite food packaging film has excellent heat-insulating property.