Chinese Elaeagnus angustifolia (EA) is a homologous food and medicine that is rich in bioactive substances, and most EA is currently treated as an abandoned resource. In this study, various lactic acid bacteria (LAB) were used to ferment EA juice to improve its content of bioactive compounds and the aroma profile to develop a nutritious and acceptable EA beverage. The growth characteristics, total phenolic content, total flavonoid content, antioxidant activity, and aroma profiles of the EA juice after fermentation by pure and mixed LAB were measured. The results of pure LAB fermentation showed that Lactobacillus rhamnosus (BL) had strong adaptability in EA juice, and Lactobacillus fermentium (BF) had the greatest ability to improve its probiotic function. 1-nonanol, 3-buten-1-ol, 3-methyl-, 2-tridecanone, pentanoic acid, and 10-octadecenal could be the typical aroma substances of coculture-fermented EA juice. This is the first study in which EA processing by LAB fermentation has been investigated. The results proved that the fermentation of EA by mixed BL and BF could be a promising method for the high-value utilization of EA.