The invention discloses a fermentation method for production of fucoxanthin by Nitzschia laevis, including the following steps of: step A, preparation of inocula; step B, fermentation culture: inoculating of Nitzschia laevis according to a certain volume ratio to reaction kettle containing sterile fermentation medium for aeration fermentation, preparing fucoxanthin fermentation broth through culture mean of fed-batch nutrient components; step C, obtaining high fucoxanthin induction culture solution by aeration induction culture under irradiation of monochromatic light or mixed light; extracting fucoxanthin from high fucoxanthin induction culture solution. The invention optimized fermentation condition by fed-batch nutrient components during aeration culture of alga Nitzschia laevis, thereby significantly increasing the cell density of Nitzschia laevis in sterile fermentation broth, and then treating high density fucoxanthin induction culture solution of Nitzschia laevis by using light treatment, inducing the accumulation of fucoxanthin, thereby further increasing productivity of fucoxanthin produced by fermentation.