The microbial fermentation of malic acid,which is one of the most important organic acid platformsused widely in food and chemical engineering, hasattracted considerable interest. A malate production strainwas isolated, a mutation was induced, and regulation of themetabolic network was then conducted. The identificationresults showed that the malic acid production strain, HF-119, belonged to Rhizopus delemar. An analysis of themetabolic pathway showed that the malic acid flux of thisstrain occurred through three main pathways, and manybyproducts, such as succinic acid, fumaric acid andethanol, were produced. Although corn straw hydrolytewas used, the metabolism of xylose was not as rapid as thatof glucose. Subsequently, breeding of the strains andregulation of the metabolic network resulted in an increasein malate yield, and the strain HF-121 produced more than120 g/L malic acid within 60 h. The ability to producemalic acid from biomass hydrolyte highlights the industrialdevelopment potential of this strain.