The invention relates to a treatment method of Acer mandshuricum Maxim. for seedling emergence in a dormancy-breaking year. The invention aims to solve the problems in the prior art that after Acer mandshuricum Maxim. seeds are sown, the seeds need to stay in nurseries for winter, thus the seedling raising time is long, the seedling emergence rate is low, and the management and protection costs are high. The treatment method comprises the following steps: (1) selecting seeds, and soaking the seeds repeatedly; (2) conducting disinfection and conducting cleaning; (3) mixing the cleaned seeds and wet river sand in proportion, and placing the mixture for 7-10 days at a temperature of 10-15 DEG C; (4) conducting stratification treatment; (5) conducting freezing, conducting unfreezing after freezing, and storing the unfrozen seeds in a cellar; and (6) placing the seeds and the river sand which are stored in the cellar to outdoor shady places for vernalization, and sieving the river sand out of the seeds for seed sowing. The treatment method provided in the invention breaks the comprehensive dormancy of the Acer mandshuricum Maxim. seeds, seedlings can normally emerge in the current year after sowing, and the seedling emergence is ordered, the seedling emergence rate can reach 82% or more, seedling raising time is shortened, the seedling survival rate is improved, the management and protection costs are reduced, and the method is suitable for breaking dormancy of the Acer mandshuricum Maxim. seeds.