The invention discloses an application of total flavones of radix cudramiae to the preparation of drugs for protecting the lever. The total flavones of the radix cudramiae are prepared by using a method comprising the following steps of: crushing dry medicinal materials of the radix cudramiae into coarse powder; adding 50-95% ethanol into the coarse powder to reflow 1-3 times, filtering, and recycling the ethanol from the filtrate to obtain a total extract: adding distilled water into the extract to sufficiently dissolve the extract and filtering; and taking out the filtrate, adjusting the pH value to 4-5, purifying by using D101 macroporous adsorption resin, collecting eluent generated by using the 50-95% ethanol, measuring to know that the purity of the total flavones in the eluent is up to 60.84-79.85%, recycling the ethanol, carrying out reduced-pressure condensation, drying to obtain the total flavones of the radix cudramiae, and preparing the total flavones into tablets, capsules, sustained release tablets, drop pills, granules, fine granules, injections and the like. The application of the total flavones of the radix cudramiae to the preparation of drugs for protecting the lever has the advantages that the medical prospect of the total flavones of the radix cudramiae is developed and a new medical field is expanded. The total flavones of the radix cudramiae contain various medical components, have prevention and treatment effects for acute liver injury and are exact in curative effect.