Antibiotics delivery using dressings is an effective manner to treat chronic infected wounds, but it still faces the challenge of uncontrolled drug release. To address this issue, we developed pH-responsive electrospun nanofibers for controlled release of poorly water-soluble antibiotics. Specifically, the drug-loaded electrospun nanofibers were fabricated via coaxial electrospinning technique, with polycaprolactone (PCL) and drug acting as the core and pH-responsive acrylic copolymer Eudragit L100–55 serving as the sheath layer. Under alkaline conditions, all drugs release rapidly due to the dissolution of Eudragit L100–55, and first-order model well fits the release behavior. In contrast, the sheath layer swells under acidic conditions, causing poorly water-soluble drugs to be firmly trapped. Moreover, the drug-loaded nanofibers display completely different antibacterial activities due to distinct drug release behaviors under alkaline or acidic conditions. The current pH-responsive nanofibers shows superior controllability of poorly water-soluble drug release, revealing great prospects for treating chronic infected wounds.