Sodium decanoate was first found to be an effective precursor for synthesis of daptomycin from Streptomyces roseosporus NRRL11379 which was increased to 71.55-fold, compared with decanoic acid. The optimal flow rate of precursor was at 600 mg/(L day) after 48 h fermentation. From protein analysis via SDS-PAGE and identification of Tandem MS/MS afterwards, it deciphered that guanosine pentaphosphate synthetase, PNPase, tripeptidylamino peptidase primarily dealing with daptomycin synthesis. By applying Taguchi’s L16 in culture optimization, the best yield was obtained from the medium with 60 g/L dextrin, 10 g/L dextrose, 1.0 g/L molasses, and 8 g/L yeast extract, respectively. The fed-batch fermentation, applied with feedback control of dextrin, stimulated the production up to 812 mg/L at 288 h. To our best knowledge, the daptomycin production in this study is significantly higher than that in previous studies and can make it more widely used in pharmaceutical industry.