The generation of chaos in single-ring erbium-doped fiber lasers (SREDFLs) is investigated by using the delay polarization feedback control. The dynamical characteristics of SREDFLs are studied by appropriately adjusting the delay time, the coupling coefficient, and the polarization angle. The routes of chaotic generation and the parameter ranges of the chaotic states are given. Chaotic generation is achieved in the SREDFLs. Moreover, the chaotic synchronization of two SREDFLs is investigated by using the method of chaotic signal driving. The results show that no matter the two SREDFLs are chaotic or periodic before being driven, they can realize chaotic synchronization with a suitable driving intensity. Furthermore, the influence of the driving intensity and the polarization angle on the quality of chaotic synchronization is analyzed by using the correlation coefficient.