Nanofibrous cellulose acetate membrane (CA) was prepared by electrospinning technique, after thermal treatment, the regenerated cellulose (RC) was obtained by fully hydrolysis of CA, then porphyrin conjugated nanofibrous membrane (RC-PPIX) was finally prepared by protoporphyrin IX (PPIX) covalent bonding via spacer arm, diethylenetriamine (DETA) linkage. The nanofibrous membranes were characterized by DSC, tensile tester and SEM to explore the thermal behavior, mechanical strength and surface morphology of the pristine CA, thermal treated CA and fully hydrolyzed CA. Chemical structure changes during the modification procedures were monitored by FT-IR and XPS. Finally, the antibacterial property of RC-PPIX was evaluated by Escherichia coli. The results demonstrate that, the mechanical strength of the thermal treated CA is improved significantly since the fiber is melted with each other and the nanofibrous structure is maintained at the same time; the successfully prepared photoantibacterial nanofibrous membrane exhibits better antibacterial property against E.coli with the illumination time increasing, the best inactivation rate is 99.999% when irradiated for 30 min with Xenon lamp.