The invention relates to a method for fermentation production of DHA, in particular a method for producing DHA through solid culture and liquid fermentation of Schizochytrium. The method comprises steps of activation of a strain, preparation of a suspension of the strain, preparation of a primary seed, preparation of a secondary solid seed, enlarging cultivation of the secondary solid seed in a fermentor, collection of cells after fermentation, and extraction of DHA oil. With the fermentation method, the seed preparation method is improved, the seed enlarging technology is simplified, the period of seed culture and fermentation is shortened, and therefore the investment is reduced and the cost is saved; in addition, the solid culture medium is of eutrophy and rich in a plurality of growth factors, and is more beneficial to the growth of the seed; cells are strong in viability and good in synchronism in solid culture medium.