The invention belongs to the technical field of microorganism application, and in particular relates to Aureobasidium pullulans and its application in producing polymalic acid. A high-yield polymalic acid Aureobasidium pullulans, which is classified as Aureobasidium pullulans GXZ‑6, and the preservation number is CCTCC NO: M 2017517, and the preservation date is September 20, 2017. The preservation unit: China Center for Type Culture Collection, deposit address: Wuhan University, Wuhan, China. Aureobasidium pullulans (Aureobasidium pullulans) GXZ‑6 provided by the present invention can utilize tapioca starch, corn starch, wheat starch, soluble starch, starch saccharification liquid, maltose syrup as carbon source fermentation to produce polymalic acid, compared with utilizing glucose as For the production of polymalic acid by fermentation of carbon sources, the cost of raw materials is lower, and there is no problem that high-concentration carbon sources can inhibit the growth of bacteria.