The invention provides a preparation method of beta-carotene bacterial powder. The preparation method comprises the following steps of adding thallus containing beta-carotene in a solution containingan emulsifier, a filler and an antioxidant, performing shearing to obtain a beta-carotene bacterial solution, and drying the bacterial solution to obtain the beta-carotene bacterial powder. The methodprovided by the invention can perform continuous industrial production and avoids the aftertreatment process and high-temperature spray drying from causing degradation and isomerization reaction on the beta-carotene.