Vacuum assisted resin transfer molding (VARTM) was a cost-effective method for fabricating wing T-shaped stringer, but the cross-section characteristics of the stringer were not conducive to the balanced resin flow during the molding process. Aiming at the problem of resin enrichment in triangle area of T-shaped stringer but insufficient wetting in edge area, the fiber filling method of corner triangle area of mold was adopted in this paper to optimize VARTM process parameters and improve the mechanical properties of T-shaped stringer. The influence of process scheme on the thickness uniformity of each part of stringer was studied. Optical microscope was used to observe the microstructure of the stringer. Moreover, the void content and fiber volume fractions were quantitatively analyzed by burning method. Besides, the mechanical properties of the stringer were tested by universal material testing machine. The results show that the T-shaped stringer formed by VARTM process has good thickness uniformity, high fiber volume fractions, low void content and good mechanical properties, the bending resistance of the stringer is increased by 15.72% and the void content is less than 1% (0.9%).