High - dose vitamin C HDVC therapy has synergistic or sensitizing effects on chemotherapy radiotherapy and targeted therapy in preclinical experiments. However the clinical efficacy of HDVC is limited which shows that there is no significant improvement in the prognosis of cancer patients. This may be related to the pharmacokinetic characteristics of vitamin C such as Vitamin C is volatile that its half-life is only 30 minutes and is rapidly excreted through renal first-order kinetics also its effective concentration duration of only a few hours. Thus after stopping infusion the plasma vitamin C concentration rapidly decreases resulting in insufficient time for the drug to reach a peak concentration or maintain an effective concentration to kill tumor cells in the body. As a cheap and low-toxicity anti-tumor therapy HDVC needs to find strategies to enhance its clinical efficacy. This article summarizes the clinical efficacy enhancement strategies of HDVC from existing clinical trials by increasing blood concentrations prolonging effective concentration durations and delaying drug metabolism which including adjusting the solvent using sterile water as the preferred preparation preparing it on site and sealing it with vacuum standardizing the dosing schedule and recommending a single dose of 75-100 g 1. 5-2. 2 g / kg administered intravenously at a constant speed of 1g / min for at least 3 times per week for 4 weeks or longer. Nanotechnology and combining with arsenic trioxide or FOLFOX can also enhance the clinical efficacy of HDVC. These strategies provide ideas and references for the standardized clinical application of HDVC in the future.