The PbSe quantum dot-doped ring-core fiber is successfully prepared using a modified chemical vapor deposition method. The fiber has a double-clad structure, with a refractive index difference of approximately 2.2% between the ring core and the inner cladding. The types and contents of elements in the fiber are verified via electron probe microanalysis. The crystal structure of PbSe quantum dots is examined using a high-resolution transmission electron microscope, and the Raman spectrum is measured. The results proved that PbSe quantum dots were doped successfully into the ring-core fiber. This provides an important reference value for preparing semiconductor quantum dot-doped fiber. The PbSe quantum dot-doped ring-core fiber is the foundation for the vortex mode amplification system. The first- to third-order vortex amplifying modes are realized at 1550 nm. When the pump power is 634 mW, the on-off gains of all modes are greater than 13 dB, and the differential mode gains are less than 2.45 dB. This experimental system is expected to promote further research on vortex mode broadband amplification.