The invention relates to a portable air filling device. The portable air filling device comprises an air filling pump body, an upper cover, a middle cover, a lower cover, an elastic complex part and an elastic air stopping plug, the upper cover and the middle cover are sealed to openings at two ends of the air filling pump body correspondingly, the air filling pump body, the upper cover and the middle cover form an air chamber, the lower cover is arranged outside the air chamber, a containing cavity is formed between the air chamber and the lower cover, the upper cover is provided with an airsuction hole, the middle cover is provided with a first air through hole, the lower cover is provided with an air discharging hole, the elastic complex part is arranged inside the air chamber, the elastic air stopping plug is composed of an opening foam arranged inside the containing cavity and an air separation layer, the opening foam is located between the first air through hole and the air discharging hole, and the air separation layer is covered on the surface, facing the first air through hole, inside the opening foam. The portable air filling device has the advantages of being small in volume, capable of being stored and convenient to carry and use.