The invention relates to the technical field of metal hot dip plating, and in particular relates to a method for evaluating a plating aid for metal hot dip plating. The method provided by the invention comprises the steps that the thickness of a plating aid layer is analyzed; the coating uniformity of the plating aid is analyzed, and at the same time the peeling mechanism of the plating aid layeris further analyzed; and the peeling temperature interval and the peeling duration are used as the evaluation indexes of the plating aid for metal hot dip plating. Whether the plating aid matches a corresponding metal hot dip plating process can be effectively judged. A necessary technical support is provided for selecting the best plating aid for the metal hot dip plating process and improving the quality of a metal hot dip plated product.