This disclosure relates to microbial technology, and more particularly to a Mortierellaalpina strain and a use thereof, a microbial oil containing ARA at an Sn-2 position, a preparation and uses thereof. Sn-2 fatty acids of the triglyceride in the microbial oil include 23% or more by weight of ARA. The microbial oil is prepared by fermentation using Mortierellaalpina strain GDMCC No. 607344.