The changes were discussed in the scavenging rate of ABTS free radicals of reduced pyrroloquinoline quinone (PQQH₂) under different mass concentrations and different reaction time conditions. The primary and secondary reaction kinetic models were established. With conventional antioxidant vitamin C as a control, the scavenging performance of PQQH₂ on ABTS free radicals was studied. Results: The higher of the concentration of PQQH₂ and the longer the time were, the higher of the scavenging rate of ABTS free radicals was. After 25 minutes of reaction, the scavenging rate of 70 mg/L PQQH₂ could reach more than 90%. The linear correlation coefficient fitted by the quasi-second-order kinetic model was 0.959～0.996, which was more in line with the scavenging characteristics of ABTS free radicals by PQQH₂. The IC₅₀ value of PQQH₂ for scavenging ABTS free radicals was 90 μmol/L, which was 51.14% of vitamin C, when the holding time was constant, the loss of ABTS free radical scavenging ability of the same concentration of vitamin C was 2 to 3 times that of PQQH₂. At a certain temperature, the loss of ABTS free radical scavenging ability of the same concentration of vitamin C was about 3 to 7 times that of PQQH₂. In summary, PQQH₂ has better antioxidant capacity than vitamin C.