The present invention provides a method for producing and purifying β-carotene by Blakeslea trispora fermentation and use thereof. The method comprises the following steps: a) separately inoculating the Blakeslea trispora strains onto a PDA culture medium so as to obtain a spore suspension; b) propagating spores in a seeding tank so as to obtain seeds for fermentation; c) inoculating the seeds for fermentation onto a fermenter and fermenting said seeds; d) adjusting the fermentation liquid to be basic by using an organic or inorganic base, and filtering so as to obtain wet mycelia; e) treating the wet mycelia with a hydrophobic non-polar organic solvent; f) mixing the wet mycelia with an organic solvent of ester and obtaining a concentrated solution by extracting; g) adding a saturated monohydric alcohol into the concentrated solution, and filtering and crystallizing so as to obtain pure ss-carotene. The content of the ss-carotene in the present invention exceeds 96%, and the yield is above 85%.