Novel p-n heterojunction of Cu2O/Bi2O2CO3 photocatalysts with various proportion of Cu2O are synthesized by the precipitation method at room temperature, which are then combined with electrospinning method and electron beam irradiation to construct a photocatalyst-polymer structure. The results indicated that the Cu2O/Bi2O2CO3 photocatalyst obtained, in contrast to the pure Bi2O2CO3, enabled improved visible-light absorption, which can separate and migrate the charge carriers efficiently via solid p-n heterojunction interfacial effect. Accordingly, the Cu2O/Bi2O2CO3/PEO nanofibers allowed for the higher visible-light-responsive photocatalytic activity for the degradation of chloramphenicol (CAP), which the highest degradation efficiency is 98.2% for CAP in 30 min and obviously higher than that of Bi2O2CO3 membrane. In addition, combining cytotoxicity experiments with LC-IT-QTOF, it is found that intermediates such as DH-CAP and NO-CAP produced during the degradation of CAP are main possible reasons for the increase in the solution cytotoxicity. Besides, the obtained materials show significant inhibition against Escherichia coli and Staphylococcus aureus with the maximum inhibition rates of 81.5% and 75.6%, respectively.