In the development process of leather industry, metallurgical industry, electroplating industry, mining industry and other industries, wastewater containing heavy metal ions is discharged to the river and farmland, resulting in environmental pollution. Heavy metal pollution has been paid more and more attention. It is an urgent problem to control the pollution and recover heavy metals. Hg2+ is considered to be the most toxic heavy metal. This article studied the modified PLGA/G5-T fibers to treat the Hg2+ wastewater efficiently. In this study, thymine-1-acetic containing carboxyl reacted with G5.NH2 to form G5-T. Then G5-T was mixed with PLGA for subsequent formation of T-modified electrospun PLGA/G5-T nanofibers. The nanofibers were characterized with fourier transform infrared (FTIR) and scanning electron microscope (SEM), and measured the sorption efficiency and selectivity by inductively coupled plasma-optical emission spectroscopy (ICP-OES). FTIR results showed that the amino groups absorption peak of PLGA/G5-T nanofibers at 3 320 cm-1 was weaker than that of PLGA/G5, the amide groups absorption peak of PLGA/G5-T nanofibers at 1 660 cm-1 was stronger than that of PLGA/G5, suggesting that G5.NH2 reacted with thymine-1-acetic successfully. The results from SEM measurements showed that mean diameter of PLGA/G5-T nanofibers was (751±72) nm, and fiber morphology of PLGA/G5-T was uniform, smooth without adhesion. It was concluded that the thymine modification would not appreciably impact the fibrous morphology of PLGA/G5-T nanofibers when compared with the PLGA/G5 nanofibers. It could be found with ICP-OES that Hg2+ removal efficiency of PLGA/G5-T was significantly higher than that of PLGA/G5 fiber membrane. The good performance on Hg2+ removal was due to the enhanced removal efficiency of thymine; absorbing test of various metal ions showed that only a little ion of Cu2+, Cd2+ and Co2+ was adsorbed on PLGA/G5-T while a lot of Hg2+ ions were adsorbed. It was proven that PLGA/G5-T nanofibers can remove Hg2+ from aqueous solution selectively and efficiently. This study is beneficial to research and development of new Hg2+ adsorbents.