The invention provides a preparation process for extracting total flavonoid glycosides from mistletoe, using mistletoe as raw material, extracting with alcohol or water, filtering, purifying with a macroporous adsorption resin column, eluting with alcohol until colorless, and using 50 Collect the eluate after elution with %-95% alcohol, recover the alcohol until there is no alcohol smell, concentrate it into extract or dry powder under reduced pressure or normal pressure, dissolve it with 60%-95% alcohol, filter, and remove the precipitate and recover the filtrate, and recover the alcohol under reduced pressure to obtain the desired total flavonoids of mistletoe. The invention also discloses that the total flavonoid glycosides of mistletoe are used as the basic active ingredient to prepare anti-cardio-cerebrovascular sclerosis and embolism, anti-arrhythmia and blood pressure-lowering drugs, and to treat and prevent cardiovascular and cerebrovascular sclerosis and embolism, arrhythmia and high blood pressure. Medicinal use for pathological conditions such as blood pressure.