A tunable oxidization and reduction strategy was proposed to directly regenerate spent LiFePO₄/C cathode materials by oxidizing excessive carbon powders with the addition of FePO₄. Experimental results indicate that spent LiFePO₄/C cathode materials with good performance can be regenerated by roasting at 650 °C for 11 h with the addition of Li₂CO₃, FePO₄, V₂O₅, and glucose. V₂O₅ is added to improve the cycle performance of regenerated cathode materials. Glucose is used to revitalize the carbon layers on the surface of spent LiFePO₄/C particles for improving their conductivity. The regenerated V-doped LiFePO₄/C shows an excellent electrochemical performance with the discharge specific capacity of 161.36 mA·h/g at 0.2C, under which the capacity retention is 97.85% after 100 cycles.