The invention provides a method for improving quality of a galvanized layer of a galvanized automobile sheet, and belongs to the technical field of steel production. The method is suitable for IF steel and low-alloy high-strength steel galvanized automobiles. The method comprises the steps that the temperature of strip steel entering a zinc pot and the ingredient of galvanizing zinc are controlled; technological parameters of an air knife are controlled; a hot-dipped automobile sheet is leveled in a finishing-liquid wet finishing manner, the value of the surface roughness Ra of the finished strip steel is controlled within 0.8 micro-meter to 1.2 micro-meters, and RPc is larger than or equal to 90; and the surface structure uniformity of the galvanized layer is improved, and the galvanized layer has the good structure, binding force and post-coating corrosion resistance. The method has the beneficial effects that existing production line equipment does not need to be modified, the surface quality and production efficiency of the galvanized layer of the automobile sheet are improved through process optimization, and the coating performance of the galvanized automobile sheet is effectively improved.