The invention discloses a spike pruning method for Benibalad grape. Watering is carried out once in the early stage of grape blooming, namely 0%-30% of the grape blooms, and the water quantity of 35-40 kg; the flower spike is trimmed after the full-bloom stage, namely 70-80% of the grape blooms, an auxiliary spike, and three to five branches on the upper part of the spike shoulder are trimmed, a spike tip is not trimmed, and twenty to twenty-three branches of the whole flower spike are kept. After the flower spike is trimmed, the width of the spike shoulder is maintained, the width of the spike tail is 3-4.5 cm, and the length of the spike is 11-13 cm. Through quantitative watering and timely flower spike trimming, the distribution of plant hormones in the spike is regulated, the hypogenetic inflorescence of grape variety with high natural fruit setting rate is enabled to realize bloom dropping and bud falling, the flower thinning effect is realized, the competing for nutrients in the blooming process of the flower buds is reduced, the size of the grape spike is controlled, the fruit size is increased, the workload of fruit thinning is reduced, and the fruit quality is improved.