Objective alpha-Galactosidases are widely used in many fields. It is necessary to improve the production of enzymes through microbiological processes. The aim of this study was to construct recombinant Aspergillus niger strains with high alpha-galactosidase production. Results Two recombinant A. niger strains were constructed: AB and AGB. The recombinant AB strain contained the alpha-galactosidase aglB gene from A. niger with its native AglB signal peptide regulated by the glucoamylase promoter. In the AGB recombinant strain, the AglB signal peptide was replaced with the glucoamylase (GlaA) signal peptide. The extracellular maximum alpha-galactosidase activity of the AGB strain was 215.7 U/ml and that of the AB strain was 9.8 U/mL. The optimal conditions for alpha-galactosidase were pH 3.5 and 35 degrees C. Conclusions The GlaA signal peptide substantially increased the yield of secreted alpha-galactosidase in A. niger. This recombinant strain holds great potential for industrial applications.