Halide scintillation crystals with neutron-gamma dual detection capabilities show broad application prospects in the field of radiation detection. High optical quality NaI∶Tl and NaI∶Tl,Li scintillation crystals were grown by Bridgman method in this paper. The photoluminescence excitation (PLE) and emission (PL), time-resolved photoluminescence, X-ray excited radioluminescence (XEL), γ-ray detection performance and neutron-gamma discrimination performance of NaI∶Tl co-doped with different Li concentrations were systematically studied. Under the excitation of X-ray, NaI∶Tl and NaI∶Tl,Li crystals show emission peaking at 345 and 410 nm respectively, which are related to sp-s2 transitions of Tl+ ion. As the increase of Li co-doping concentration, the light yield of the crystal decreases from 41 000 photons/MeV to 23 000 photons/MeV, while the energy resolution at 662 keV deteriorates from 7.0% to 9.6%. Among the tested samples, the NaI∶Tl crystal co-doped with 1% Li has the best neutron-gamma pulse shape discrimination (PSD) performance, and the neutron-gamma PSD figure-of-merits (FoM) reaches 4.56.