The invention relates to a cold-proof method of grape, in particular to an overwintering and cold-proof method of outdoor grape. The method is characterized by comprising the following steps of: a. preparing a polystyrene foam grain carpet; and b. paving the polystyrene foam grain carpet under an outdoor grape bracket. The method is unique, is applied to the outdoor grape in the rest period in the North China, adopts the material which is low in price, good in heat preservation, light in weight, low in water absorption, labor-saving, time-saving, and easily paved and furled for preventing late frost in winter, prevents the buds of branches of the outdoor grape in rest period from being frozen and covered, prevents the branches and tendrils of the outdoor grape in rest period from losing water, and prevents the roots of the outdoor grape from being frozen due to the temperature in the covering material.