To screen excellent microbial for silage additive usage, 5 lactic acid bacteria strains were isolated from exogenous bacteria powder. By analyzing strain morphological, physiological and biochemical characteristics and combinating16s rRNA method to identify lactic acid bacteria. By contrasting lactic acid bacteria growth curve and producing acid speed of exogenous and conventional superiority strains, It gets three high-performance lactic acid bacteria strains and compares the biological characteristics of three strains bacteria. Results show that R 1 and R 5 are lactobacillus plantarum; R 2, R3 and R4 are Enterococcus?faecium; Strain R 1, 7, R 5 grows fast and the ability of producing acid is better; T > 50℃, The heat-resistant ability of R 1 is better than R 5 and 7, pH < 2.5, The adaptive capacity of R 1 is better than R 5 and 7. The bacteriostatic ability of R 1 is better than others, Exogenous varieties R 5 as a excellent Lactic acid bacteria for silage additive usage.