The invention relates to a nutrition supplementation forage and a preparation method thereof for cows in lactation peak period. The nutrition supplementation forage for cows in the lactation peak period is prepared from the following raw materials in parts by weight: 4-13 parts of puffed corn, 6-14 parts of yeast culture, 3-15 parts of corn gluten meal, 5-50 parts of extruded soybean,10-60 parts of fractionation saturated fat,10-20 parts of potassium chloride, 0.44-1.94 parts of rumen bypass choline and 0.06 parts of antioxidant. According to the nutrition supplementation forage and the preparation method, through strict selection of the raw materials and reasonable formula design, the match proportion of the nutrition and energy is balanced. Therefore, nutrient concentration of the forage can be rapidly increased; energy that is scarce in the cows can be supplemented; the rumen digestion rate is strengthened; the organism fat metabolism is promoted; the nutrition supplementation forage and a preparation method enable the milking cows to rapidly increase milk production, increase body condition and avoid the ketosis and abomasum displacement.