A method of preparing nano-dispersed high-all-trans-carotenoid microcapsules is provided, comprising: preparing 10-20% carotenoid suspension by milling the high-all trans-carotenoid crystals with dichloromethane until the particle size thereof is in the range of 2-5 μm, then supplying the suspension together with preheated dichloromethane of another pass into a dissolving tank to obtain a solution of 0.5-2%; delivering the solution together with ethanol or isopropanol into a crystallization device having high gravity rotating packed bed simultaneously and continuously, and then into a wiped-film evaporator for desolvation until the solid content is 10-20%, then a transparent alcohol dispersion of carotenoid is obtained; mashing the alcohol dispersion together with an aqueous solution containing an antioxidant and protective colloid and spray drying to obtain nano-dispersed high-all-trans-carotenoid microcapsules. As the crystals are nano-dispersed and the content of trans-isomer is more than 90%, the carotenoid microcapsules of present inventions exhibit high bioavailability.