The present invention relates to a method to produce biodegradable polyester, which comprises the following steps: (a) mixing a carbon source, a nitrogen source and water into a reactive material to perform pretreatment; (b) providing a halophilic bacterium, a starting broth and culture with the reactive material; (c) feeding the reactive material; and (d) extracting the polyester from the fermentation broth; wherein, the bacterium has a salt tolerance of 10-30%.
